The ZDoom Community Map Project "Take 2"

ZDoom Community Map Project: Take II, abbreviated to ZDCMP2 is a single map for ZDoom designed by a large number of mappers. It is one of the largest levels ever made. Like the previous project, each mapper was assigned a set of dates to work on the map, each one continuing where the last mapper finished. It took over two years to build, with a final release on 25 May 2014. The map makes extensive use of ZDoom features, such as 3D floors (including swimmable water), and portals. The second release candidate, released on 9 December 2013 won one of the 20th Annual Cacowards.

Data logs
Throughout the level, the player will come across data logs of the since deceased base personnel. Many of the personnel are named after the developers of the level, though some are named after characters from popular culture. There are 21 data logs to be found in total. The player also has their own data log, which they can use to view their current objectives. This uses a separate keybind, and again, the player must define it themself.

Data logs essentially serve the same purpose as the PDAs in Doom 3. They play a large part in telling the story of the level, and also drop hints, telling the player what to watch out for, or what they need to do.

New monsters

 * Zombie scientists: Added to the zombie roster are scalliano's iconic scientist zombies. They can only attack with melee and move very slowly, so pose very little threat. They come in two varieties: Males, who are armed with an axe and have 20 health; and females, who carry a knife, and have 15 health, meaning they can be potentially killed with a single pistol shot. Neither scientist drops anything when killed.


 * Rapid Fire Trooper: A low-tier zombie that fits perfectly between the sergeant and the trooper. Like the trooper, he shoots with an assault rifle, but at a much higher rate, faster than the player's own pistol. Like the sergeant, the rapid fire trooper has only 30 health, so can easily be taken care of. They drop the rifle when killed, and can be identified by the distinctive brown colour on their body armour. They are among the first monsters encountered in the level.


 * Flesh Spawn: One of the more grotesque enemies in the level, the flesh spawn is a small spherical flying demon, completely featureless aside from a large mouth where its face would be located. Judging by the similar projectile, its ability to fly, and its blue blood, the flesh spawn is most likely some form of cacodemon larvae. Fortunately, it has just 30 health, so every weapon can make short work of it. Always encountered in swarms.


 * Shadow: A small humanoid demon that maintains a crouched position. Their skin is black, but also slightly transparent. They are often found in dark areas, where they are extremely difficult to spot, and their presence is easier to identify by their iconic growling. Their position is also given away by the fast-moving red projectile that they throw at the player. They have 80 health, so a single shotgun blast may not always be enough to take one of these down. As you'd expect, shadows drop nothing when killed.


 * Soul Harvester: Visually, the soul harvester appears to just be an imp with grey skin. However, in combat, it functions slightly differently. It takes some time to create its projectile - a yellow sphere showing the face of a demon - then launches it at the player, where it will follow the player, and due to its great turning circle, it is rather difficult to avoid. With 100 health, it should take two shotgun blasts to kill one of these. They are one of the few monsters that appear continuously throughout the level.


 * Grell: A brown airborne demon, very similar in appearance to the Doom 3 Cacodemon. They spit a poisonous green projectile that on impact will give a green tint to the player's screen, and will slow the player down for three seconds. They are encountered solely in hellish settings, making their first appearance rising out of the portal inside the dig site. They have 300 health.


 * Hell Warrior: A medium-sized demon with orange skin and a lions mane. They appear to be related to the hell knight and baron of hell. They launch a yellow version of the baron's projectile, and if necessary, take cover behind their shield, which is also capable of shooting a green projectile.
 * They have 400 health, slightly less than that of the hell knight.


 * Vore: The vore is a three-legged monster taken directly from Quake. It functions identically to its original counterpart, throwing purple spiked bombs that home in on the player, exploding on impact. Like the projectile of the soul harvester, "Voreballs" have a large turning circle, so avoiding them can prove challenging. The vore is tougher than its original counterpart however, with 600 health.


 * Cybruiser: A devastating combination of the Baron of Hell and the Cyberdemon. This dark grey baron has had its right arm removed and replaced with a very powerful rocket launcher, and like the cyberdemon, fires three rockets at a time. At 1250 health, they are slightly tougher than the standard baron.


 * Bruiser demon: A giant baron-like demon, easily identifiable with its bright orange torso and black legs, and by its distinctive roar. The bruiser demon has three different attacks, it can either launch a spread of seven small fireballs, a single large one, or send three lines of fire towards the player along the ground.
 * Bruiser demons only appear in Hell, and even there, they are rarely encountered, but when they are, they will be in pairs. They have 1500 health, making the rocket launcher or plasma gun a favourable weapon for taking them down.


 * Angel of Death: A tall, brown, hoofed demon with a skeletal face and a grey, hooded cloak, first encountered as the eponymous specimen in specimen containment. The angel is armed with two machine guns, of which the bullets rebound off walls, and mounted on its chest is a small explosive cannon.

New weapons

 * Rifle: Weapon slot 2. Dropped by the rapid fire troopers, the rifle is a bridge between the pistol and the chaingun. It fires two bullets at a time at a slightly slower rate than the pistol. It has an alternative fire where it will shoot one shotgun shell. The shell attack takes very long to reload, and since the shotgun is received early on in the map, and the chaingun not long after, the player is unlikely to use the rifle past the first few minutes of the map.


 * : Weapon slot 3. The AA-12, when found, will replace the default shotgun. It does the same amount of damage, but has a much higher rate of fire, making it a very powerful weapon. Unfortunately, it can only be found in a secret area (see below, secret #25), which is very close to the end of the level, bringing the weapon's usefulness into question.


 * Nailgun: Weapon slot 4. Hailing from Quake, the nailgun is a decent alternative to the chaingun. The nails that it will launch at the enemy are more powerful than the chaingun's bullets, but the nails also travel as a medium speed projectile, taking longer to reach their target. The nailgun's rate of fire is also slightly lower than that of the chaingun. Ultimately, this makes the nailgun a very good close quarters weapon against mid-high tier monsters, but at longer distances, the chaingun is the weapon to use.


 * Flamethrower: Weapon slot 5. Retrieved from the weapon lab, the primary purpose of the flamethrower is to burn through the vines that are encountered about midway through the map. However it can be used as a very effective weapon against monsters, as it has a very high rate of fire - no pun intended!
 * If a larger number of monsters are being faced, the player can use the flamethrower's alternative attack, which will eject the fuel that is used as ammo, and then ignite it all in one go. One thing to note is that this can also be triggered by enemy projectiles, so unintentionally premature ignition can occur. The player can not be damaged by the normal attack, but can be damaged by igniting the petrol. If the player's napalm ammo is under 50, they can use a fuel station to bring their ammo up to 100 on ITYTD, and 50 on other difficulties.


 * Dark claw: Weapon slot 6. The Dark claw can first be found in the research annex, not far from the dig site. The player should take caution when picking it up, as it will be already firing purple projectiles in every direction that rebound off any surface it impacts. These projectiles are actually the primary attack of the dark claw, and addition to rebounding off surfaces, they will also home in on the nearest monster. The claw also has a secondary fire, which shoots a red beam, which drains enemy health and transfers a fraction of it to the player. The claw uses souls for ammo, and happens to belong to the final boss.


 * Soulrender: Weapon slot 7. An extremely powerful weapon. On ITYTD, the soulrender is given to the player just before the final boss fight, but if the player is on a different skill level, they will have to find the secret area containing it. Using souls for ammo, the soulrender needs to be charged up to a certain extent to fire. The progress of the charge can be seen on the weapon as white beams that light up when that charge is complete, with each beam representing a different stage in the charge. At least one beam needs to be lit to fire the soulrender, at which it will fire a white projectile that may or may not be orbited by a number of smaller white projectiles, depending on how much it is charged. At full power, the soulrender rivals the BFG9000 in power, though be aware that it will take over five seconds to charge it fully.


 * Grenades: You will be required to bind a key to use grenades. Pressing that key will throw the grenade, where it will wait a few seconds before detonating, resulting a powerful explosion. Alternatively, you can hold the key down to cook the grenade, then throw it for a smaller delay before the explosion. If you cook the grenade for too long, it will explode in your hand, dealing 200 damage.

New game +
When you finish the level, a credits sequence will begin to play. When this finishes, the level will restart, and an information box will appear at the top of the screen, telling you that you have started New Game +. This is an optional challenge for experienced players, where there are some significant differences, which include the following.


 * As you'd expect, there are more monsters. Initially there are 1262 monsters in the map, opposed to 1069 on ultra-violence. Most of these additional monsters are flesh spawns, but watch out for particularly nasty changes:
 * Three angels hide behind the doors to the dig site, bringing the angel count in the area to seven.
 * The central junction contains three cyberdemons.
 * There are two abaddons.
 * In addition to the ones already existing, many types of monster have had their numbers increased as some stock monsters have been replaced with a tougher monster that is related in some aspect, for example, all barons in the level have become the deadly Cybruiser.

Walkthrough
ZDCMP2 is one of the biggest levels ever created. Completing this level can take over a couple of hours, and the sheer size of the level will cause very low framerates on less powerful computers, which can severely amplify the magnitude of difficulty. It is highly advised that you save often! The level is intended to be played with jumping, crouching, and freelook enabled. Note that the level is highly non-linear, the following walkthrough is only one example of the order in which areas can be visited.

Entryway
You start in a small room. The exit door is present, but inaccessible for now. A door marked "weapon lab" is in front of you, but does not open. You are investigating a distress call sent by the base, and your orders are to contact Dr. Daniel Gimmer, a UAC scientist.

Head over to the large silver door, and press the switch on the left wall to open it. As you do, you see two zombiemen opposite, and you realise the base has fallen victim to a demonic invasion. Advance into the entryway, turn right and head up the stairs, where you can find a rifle, a green armor and the body of Dr. Gimmer, whose data log lies by his side. Taking the data log will cause the lift on the other side of the room to raise, rendering it usable. Upon reading Gimmer's data log, you learn he was trying to get to the eastern complex to radio for help, but his path was blocked by some hellish vines, which are found next to his body. He tells you that you need to secure the dig site, but to do that you need to find the blue passcard to get to the networking hub, which involves disabling the lockdown at the security station.

Obtaining the blue passcard
Go over to the lift, and when you are on the upper platform, follow the corridor to find a switch that opens the door opposite the lift. Continue to make your way through the room, making sure to grab a shotgun in the storage area. Proceed to the next room - a circular hub area - and turn left towards the tech lab (you may find it beneficial to first go across the nukage leak and go up the stairs to where the sergeants are, which causes the wall to lower, revealing a small alcove with two chaingunners, whose weapons you can take.) When you enter, you will encounter zombie scientists and shadows for the first time. If you are unfamiliar with shadows, it may be wise to exercise caution in this area, so you can observe and learn their relatively odd behaviour. After the tech lab is clear, continue through the doors to Waste Processing. At the top of the stairs, turn right and follow the computer screens displaying the blue passcard. The narrow door which is displayed to hold the blue door leads to a short corridor containing two of the surprisingly few revenants that populate the level. Kill them, then go to the end of the corridor, and ride down the lift. This dumps you in a corridor lit by green light, overlooking the blue passcard which is guarded by two hell knights. Pressing the switch at the end of the corridor disables the lockdown, making the blue passcard accessible. As it lowers, a small tunnel will open behind you, and some flesh spawns will pour out of it and begin to attack you. Simultaneously, four cybruisers teleport into the room with the passcard. Fear not, for they cannot attack you through the glass.

Go back the way you came, and at the tech lab/security station junction, turn right and go through the door. Clear the enemies, and jump down to the lower level. Go straight on, and you will encounter the arachnotron and the soul harvester for the first time. As you round the corner, you find the door to the blue passcard room. As noted in the monsters section above, Cybruisers are very dangerous opponents, and your lack of weaponry and ammo at this time makes it very inadvisable to enter the room and fight them directly. Instead, head over to the next security station sign and go up the stairs. Clear the zombies, and then pick up the data log of First Technician J. Paddock. His log tells you that anyone who tries to steal the blue passcard can be punished by releasing potentially lethal gas into the room. Do this by pressing the switch next to the screen, then press the screen to watch in detail as the six demons die an unpleasant death. Once they are killed, the gas stops and is purged, making the room safe to enter. Make your way there and take the blue key. When you do this, your objective log updates, telling you the next stop is the Networking Hub.

Networking Hub
This next step can be completed later, but since the area is so close to where you receive the blue key, you can do it now. Turn left out of the passcard room and head to the other security station. Go round the central line of computers to find a terminal with the blue passcard on its screen. Press it, and a panel immediately to your right will open, revealing a passage containing several flesh spawns. Follow the tunnel, and you will emerge in the room between two forcefields that link the security station and specimen containment. Clear the monsters in this room, and go up the short flight of stairs, and press the switch to deactivate the forcefields. Beware of the arachnotron, who may be trying to shoot you already. Even though you require a red passcard to proceed to specimen containment, you can still retrieve the rocket launcher that lies next to the door.

Return to the security station, and go on to the platform as if you were going to the blue passcard room. Go past it, and hit the switch at the end of the walkway. This raises the bridge and lowers the bars, which allows quicker access to the communications centre from the security station. It is now time to venture outside, and you can leave the building either by taking the left path from the bridge through the comm centre, going up the stairs to the megaarmour, and then jumping out the window, or you can turn right, returning to the hub area, turning left towards the signposts marked networking hub and courtyard. The latter route enters the courtyard nearly opposite the networking hub entrance, so it may be easier to find this way. Enter the networking hub, and you encounter the hell warrior for the first time. At the end of this small room is a computer displaying a signpost for the yellow passcard. In front of it lies a data log, which belongs to. The data log warns of large boulders that can roll down sloped terrain, and that you should exercise extreme caution if entering the area. Head over to the sign saying networking hub, and take note of Dr. Jones' hat lying on the floor. Turn to face the tunnel before entering and you will see the boulder at the top of the slope. Advance forward slowly, and when you stand roughly where the hat is, the boulder will begin to quickly roll towards you. It is important you avoid the boulder, as it will kill you instantly. Proceed up the slope, and on your left is a hell knight. Look to the right and you see another boulder. If you are quick enough, the hell knight will still be in the boulder's path when it triggers, which will save you a fair bit of ammo. Enter the building, go round the boxes past the yellow door, and continue to the next corridor. You can open the door on your left, which leads back to the small rock area where the first boulder is encountered, but be aware you need the yellow passcard to go back through. Turn right and cross the bridge over the small lagoon. If you happen to fall in, be very wary of the several naval mines that will explode upon being shot or being touched. You also need to be careful not to be underwater for too long, as you will begin to drown otherwise. Some custom HUDs have an air supply meter, allowing you to monitor this. To get out of the water, swim to the wide area of water, turn left into the small cave, then find the surface. Watch out for the shadow waiting at the water's edge, as you may not see it immediately. Go up the ladder, and you will find yourself near the blue door.

Alternatively, you can fall in deliberately, then head to the right side of the lagoon and into the cavern there. Follow this past the intersection with the bars, and surface. Watch out for the shadows. Press the switch, and submerge again. The bars will now be open, so now go to the other path from the intersection. When you surface, clear the enemies. Proceed into the next cavern, where you will be faced with either two cybruisers or a baron of hell, depending on the difficulty level. Grab the plasma gun by the crate, and take down whichever monster(s) you are faced with. Once they are killed, the vines blocking the switch to open the door will clear. The door leads you back into the security station. This step is not necessary, but is highly recommended, as there are some encounters coming up where it is the weapon of choice, and the next plasma gun is not found until after these.

Once over the bridge, follow the the corridors until you come to a large room with a high number of scientist zombies. Clear the enemies, then jump onto the crate, then up onto the ledge. Head back along this ledge, and go through the crumbled wall, then pick up a blank passcard and a data log belonging to Dr. A. Luke. This data log mentions a simulation room, where you can practice combat, and take damage, but there is no risk of death. It also mentions that First Technician Paddock managed to view some of the base access codes while in the simulation room.

Simulation room and yellow passcard
You will need to download an access code on to the blank passcard to change it into the yellow passcard. To do this, you need to enter the simulation room. Press the switch in front of you, and the large door labelled networking hub will open. This room contains some revenants, and on higher difficulties, arch-viles. Once you've killed them, press the switch on the panel in this room. This opens up the portal to the simulation room. Enter.

The simulation room has a very surreal appearance, which emphasises that it is entirely computer generated. If you fall off the simulation area, you teleport back on to the arrival pad. If you die in the simulation room, you simply arrive outside the portal again, as the death is merely simulated. Red areas in the simulation room will remove health, and blue areas give health. You also have infinite ammo in this area, so if you have it, the plasma rifle is definitely the weapon of choice for this bit. Head across the combat area, then press the switch. Simulations of cacodemons, pinky demons and imps will begin to pour out of the green and yellow structure in the middle. Green monsters have the same health as their normal counterparts, yellow have slightly more, and red have more again. Upon "killing" all of them, a large number of yellow passcards will begin to erupt from the structure. You need only take one to receive the passcard. Upon leaving the simulation room, your objective log will update. Your orders are now to proceed to the dig site via the Central Junction.

Central junction and red passcard
Go back the way you came. When you get to the small room you first entered after the second boulder, go through the yellow door, and enter the teleporter at the end of the corridor. This brings you back to the start area. Proceed to the large double doors in the entryway marked central junction, and open them. Tread carefully from here. Kill the imps that are either side, then move forward to take the soulsphere, the super shotgun and the data log. The data log, which belongs to Sgt. J. Cresswell warns you of what is now to come. He tells you that the dig site entrance is blocked by some hellish vegetation, and guarding it is "one of those cybernetic beasties." Moving to the side of this area will alert the "cybernetic beasty," who is flanked by three cybruisers. Unfortunately, it is not possible to cause infighting between them, so you will have to tackle them directly. Again, the plasma rifle is very useful to have in this situation. You will need to kill the cyberdemon and the cybruisers to lower the platform the red passcard is mounted upon. Using the flesh that envelops the platform, jump on top and grab the passcard.

The angel and the flamethrower
When you take the red passcard, your objectives log updates. It now tells you that because the way to the dig site is very clearly blocked, the only way to get there is via the eastern complex, but as you discovered at the start of the level, that too is blocked off by some hellish vines. The red passcard is labelled with "specimen containment," so that is where you need to head to next, in the hope you will find some pyrotechnics along the way.

Leave the central junction via the western door, which brings you back out into the courtyard. Go up the lift and turn left into the building, and follow the signs to specimen control. If you haven't already, you will need to deactivate the forcefields to get there in the security station. If you're yet to do this, the walkthrough for this step is in the first paragraph of the Networking Hub section above.

When you reach the red door, enter. You find a small room with several monsters, and a switch. Pressing the switch will open teleporters to the watch tower, but it is not essential to go there, so it is not covered in this section. Instead, proceed to the next door, and on the other side, you find a small courtyard, populated by some low tier monsters and a baron of hell. At the far end of the courtyard, you see the specimen containment facility, which appears to be occupied by what at a first glance looks like a statue. In front of you is a data log belonging to, who handled a "weird-ass" shipment addressed to Dr. Acheron, called the Angel of Death, which is the specimen in the hold in front of you. The data log also tells you that a prototype flamethrower can be found in the weapon lab.

Have your rocket launcher ready. Move forward and step onto the central island. The forcefields will deactivate and the angel will awaken. It is armed with two machine guns that fire projectile based rebounding bullets. You should be able to avoid most damage if you keep moving. About ten rockets should bring down the angel. Once this is done, a teleporter pad will lower in the container the angel was stored in. This will take you to the outskirts of the base. Being careful of the cacodemons and lost souls that emerge from the cliff side, as well as the zombies that can snipe you from the roof, make your way into the weapon lab. Head up the stairs and watch through the window as three scientist are burnt to death. Enter this room, and turn right to see the flamethrower on a pedestal. Take it, and the objectives log will update, and at the same time, the platform will start to lower. You are then attacked from all directions by over a dozen scientists, accompanied by a couple of shadows, giving you the perfect opportunity to try out the new weapon.

Search around the rooms that branch off this area for some napalm canisters, then head for the corridor which ends with some vines blocking a door. Use the flamethrower to burn the vines, and proceed. Hit the switch to open the door, and you find yourself back at the start area. Now go to the door to the eastern complex, where you found Dr. Gimmers body, and burn through the vines there. As you approach the door, the music changes, and your objectives log will upon opening the door.

The dig site
Your objectives log tells you that you are getting quite close to the dig site, and that to get there, you need to proceed through the engineering bay. Going through the door, this corridor leads you to the Eastern Complex, but the door to get there is blocked by some metal bars, so instead, climb through the hole in the wall just to your left. This brings you into a large storage cavern, which contains a large number of soul harvesters, so be ready to outmanoeuvre a lot of homing projectiles. Follow the cave round, and as you pass the second corner, you alert the spider mastermind who is on your right. If you can get the plasma gun and its ammo nearby, it will be very helpful in this particularly difficult fight. Once you have downed the mastermind, turn around and climb up the cavern and you should find the door to the engineering bay. Watch out for pain elementals in this area. Also be wary of approaching the marble column behind you, as it contains an arch-vile (or a baron on the lower two difficulties). Enter the engineering bay, take down the hell knights, and venture across to a lift, which lowers into a partially underground area, populated by shadows. Enter this area, then look to your left and you should see another cave higher up, which to get to, you need to jump over some platforms. Saving here is highly recommended, as low framerates make this very challenging, and if you fall into the lava, you will die. As you cross, watch out for the mancubus who is on a higher level on the other side of the chasm. Kill him from a distance, then go over the bridge to where he was hiding. Have the chaingun, flamethrower or plasma gun ready, because when you cross the bridge, the door back in to the engineering bay will open, and simultaneously, you will be attacked from the left by a large swarm consisting of either twenty-three (ITYTD, HNTR) or twenty-four (HMP, UV) flesh spawns. Once cleared, enter the building, and press the fleshy switch. You will find that the bars have now lowered, and two cybruisers are now stomping around the room. Once you have killed these, drop down into the gap in the floor, and turn right towards the dig site sign. Jump across the gap in the bridge, and continue forward, passing over the fleshy mass on the floor. This was previously blocked by bars made of flesh, this was why the eye switch was significant earlier.

Now be careful, because the angel you faced earlier was not the only one of its kind. As the entrance to the dig site comes into view, you will see either one (ITYTD, HNTR), three (HMP), or four (UV) angels on top of the perimeter. Either one or two of these angels will teleport to ground level on HMP and UV respectively, and any remaining angels on any skill level may also teleport down later. Unless you're playing on ITYTD or HNTR, this fight is quite easy to underestimate, as one angel on its own is not difficult to take down, but as many as four can be a sizeable problem. Fortunately, a decent amount of ammo is scattered around the dig site's perimeter. Once all angels are killed the doors to the dig site open, revealing a number of arachnotrons and a massive hole in the centre, which seems to have hundreds of spirits rising from it. Once you have tackled the arachnotrons, enter the dig site. As you do, grells make their first appearance, rising from the pit. Once you have killed them, take some time to go up on to the ramparts and collect some supplies. Whilst up there, you will also encounter the second data log of Sgt. Cresswell, where you learn that before the invasion, to Cresswell's annoyance, the dig site was empty, and he, along with other security forces seemed to be guarding nothing.

Hell introduction
Jump into the pit. The music will change to some unsettling ambience, and from the flesh tunnel in front of you, flesh spawns will begin to attack. From here on in, stock monsters are quite a rarity, with soul harvesters and shadows taking over completely as the main low tier monsters. You realise that if the pit you just jumped into stays open, the demons will never stop emerging from it. It has to be sealed somehow. As you emerge from the other end of the tunnel, you can return to the base by stepping onto the nearby teleporter, which leads to a small marble area just outside the dig site. Turning left will lead you down a dark corridor which ends with a door requiring a blue skull key. Since you don't have this yet, turn right. You will come to a small green room with ominously pulsating green light. In front of a switch is a megasphere. Take the megasphere and press the switch. The room begins to transform into a staircase beneath your feet. This reveals the next room, where you will be attacked from multiple directions by shadows. This room also marks the first appearance of the vore.

Once you have dealt with all this, proceed to climb over the small pillars on the other side of the room, and pick up the data log. Before you read it, it is best to tackle the small group of soul harvesters who will approach you from around the corner. Once these are killed, you read the data log, which belongs to Dr. Björn Ostmann. His data log states that Dr. Gimmer was right that the gate is being held open by a huge power source, presumably technology stolen from the UAC. He also states that Dr. Acheron had entered Hell with him, then ran ahead, "babbling" about gate keys and "The final gate." Ostmann was convinced neither he or Acheron would survive.

The gate keys
You infer from Dr. Ostmann's log that you need to find the gate keys. Proceed forward and open the door. Enter the blood tunnels, and take the path on your left. Watch out for grells. When you come to the building, enter, and find your way to the surface. This brings you out inside a lava cavern. Across the lava pit, you will see the first two bruiser demons, guarding the red skull. It is recommended to deal with them now, at a long distance, as they are far less dangerous. Once you've killed them, go round the front of the building's exterior, and follow the path downwards. Again, do not fall into the lava, as it causes instantaneous death. Go through the small cave, and you should meet two hell warriors at an intersection. Kill them, then turn right, and right again. Climb the caves and you will come to the area where the bruiser demons were, and hence you can take the red skull.

Return down into the cave, and head for the marble steps. Make your way along the walkway, into the next area. As well as hell warriors on the path with you, watch out for soul harvesters and shadows that attack you from outside, and also the vores at the end of the walkway. Go down the stairs at the end of the walkway and turn right. Taking the attacking monsters down along the way, go along this corridor, and find the metal steps with green torches. Go up these, and open the door on your right. Clear the monsters, then press the switch that is hidden behind the books right of the door. This opens the room opposite the one you are standing in. Enter that room, then open the door on your left, then take the walkway on the right. Drop down into the courtyard and take the yellow skull. Press the switch in front of you, and on your right, behind the bars, you can only watch as a large number of scientist zombies appear and decapitate the three captured marines. As they finish the executions, the barrier separating you from them will lower. Kill them, then press the gargoyle switch to lower the lift back up to the walkway. Go back through the door, and then head for the small square door to the left. Inside is a teleporter. Enter.

The final gate
The music shifts again to more disturbing ambience, and you find yourself on the outskirts of a large courtyard. Hanging over the final gate is the icon of sin, but worry not, for it does not attack or spawn monsters. Be careful when entering the courtyard though, for a large number of shadows are inside the surrounding structure. Also be wary of cybruisers attacking from the castle to the left. To open the final gate, you need to find two switches, each requiring one of the skull keys. These can be done in either order.

Red switch: Turn left in the courtyard and look for steps leading down to the castle. Go over the drawbridge and enter. Take down the monsters and proceed through the corridor, then go up the stairs. Continue to follow the corridor here, and go through the door. Cross the drawbridge, and hit the switch. Off in the distance, the icon will let out its pained roar. Jump down onto the rocky steps below, and return to the courtyard.

Yellow switch: Turn right in the courtyard. You will see the entrance into this building just below. Simply running forward should be sufficient to cross the gap, but be careful, as there is lava below. Follow the stairs round, killing the enemies as you go. When you get to the top, turn and proceed along the platform. Follow this all the way along, then turn left into the wooden section, and go down the stairs. The yellow switch is at the bottom.

With both switches pressed, the ground will begin to rumble and you hear the roars of two bruiser demons, as well as the famous reversed message of the icon of sin, though there is no monster spawner. Jump back onto the courtyard, and you will see that the final gate is now open, and the two bruiser demons stand behind where it opened. Kill them, then proceed through the gate.

Conclusion
Far in the distance, you see three tremendous towers, simultaneously emitting large explosions. Between them, there is a large orb of energy. You have found the power source mentioned in Dr. Ostmann's log, and now it is time to bring it down.

Proceed down the stairs. When you reach the bottom, a platform will rise in front of you. A megasphere is in the centre. Next to it lies the body of Dr. Acheron, who managed to make it this far through Hell, before finally being killed. The question is, if he managed to make his way past everything you just killed, what could have finished him here? The answer is found in his data log, found next to his body. It details Acheron's final seconds, in which it is implied that he deliberately opened the portal to hell, in order to find "the destroyer," also named Abaddon. If you are playing on ITYTD, be sure to take the soulrender near Acheron's body, if you don't have it already. At the sides of the platform is a long staircase. Follow it down to the bridge leading to the towers, and then cross the bridge.

When you step off the bridge, it will begin to lower into the lava below. There is no going back. Forcefields will appear on the outside, to stop you falling off the platform into the lava. Some energy orbs will appear, and from them emerge two large demons, armed with rocket launchers similar to that of the cybruiser. These are Abaddon's bodyguards. When you have killed them both, an even larger energy orb appears between the towers, and from it emerges Abaddon, a huge monster that easily dwarfs the cyberdemon and spider mastermind in size. At the top of your screen, its health will be displayed as a percentage. The exact health value for Abaddon is 12000, so you are well advised to use the BFG9000 or the soulrender here. If you have neither, the plasma gun will have to suffice. It is absolutely vital you keep moving. When Abaddon's health drops below 50%, the three towers will lower, and out of each emerges a bodyguard. While still avoiding their attacks, you should focus primarily on Abaddon. When Abaddon is killed, any bodyguards left will die with it. Unfortunately, this is not the end of the level. When Abaddon dies, ground begins to shake and the platform and the towers will begin to sink into the lava. If you have a low framerate, this is by far the hardest part of the level, as speed is essential.

Quickly go to the south-west corner of the platform and jump on to the lava island below. Jump across the next islands, then look down for the rocky path below and jump down onto it. Follow the path up, and you will eventually be attacked by some shadows. From here, you must only attack the demons if they're blocking the path, as you will not have enough ammo to take down all of them. Concentrate on following the path and avoid any projectiles. Stick to the path you are on, and follow it down. Watch out for grells. At the bottom of the past, you will need to jump across more islands, this time being attacked by grells from behind, and shadows off in the distance. Cross the islands, then jump up the steps to where the army of shadows are shooting from. Kill any that are blocking and keep running, continuing up the steps, where soul harvesters are added to the mix. Follow the path round, and jump down into the next cavern. Watch out for soul harvesters gathering at the entrance. Turn right, and head towards the next swarm of shadows. Keep following the path. Eventually, after breaking through another large horde of shadows, you will need to jump across a lava river. After doing this, turn left. Approach the next swarm of shadows, but turn right at the junction where you meet them. Run past the soul harvesters and then turn left into a room containing two angels. Run past them, then go up the stairs. At the top of the stairs you will find a flesh tunnel. Continue through it, and you will emerge in the central junction, where you encountered the cyberdemon. Run through the central junction, back to the entryway, then run through the exit door and towards the helicopter to finish the level.

If you have it enabled in options, a long credits sequence will now play, where a camera flies through the level, with messages at the top naming each area and the people who designed it. At the bottom, a sequence listing the full development team begins, with an often humorous quote from each of them.

Secrets
The console command "secret" can be used to get a list of missing and discovered secrets in the level.
 * 1) Sector 285: The first secret is accessed from the Entryway. After you go up the lift, on the way to the switch, jump onto the crates from the corner. Turn to face the window on the corner opposite. You will need to straferun and jump off the crate to reach the ledge. Proceed through the window, and fall into the water, thus triggering the secret. Grab the soulsphere and then resurface to return to the base.
 * 2) Sector 3792: The second secret can be found in the storage room where you obtain the shotgun and the first grenades. As you move towards the north side of the room, note the line of armour bonuses. The doors behind them can be opened. Inside are more armour bonuses, some shotgun shells, and a demon on all difficulties. In front of the computer screen is a data log belonging to Dr. Acheron. It contains an excerpt from his journal titled "Project Babel," a study into an alien species (the demons) of unknown origin.
 * 3) Sector 4751: The room after the storage area mentioned above is a small hub area leading to different parts of the base. Turn left towards the tech lab. As you approach the double doors that open to reveal the tech lab, note the inset panels on your right. The last one before the doors is brown, as opposed to the green ones before it. This panel opens to reveal a small room with coloured lights pulsating through the visible light spectrum. As you enter, beware of the zombie scientist immediately on your right. The room contains a stimpack, an energy cell, and a grenade. Additionally, you can press the long wall of this room, which will cause it to lower, revealing the Half-Life Easter egg room.
 * 4) Sector 4741: From the same small hub area mentioned above, go to the area marked with specimen control and security station. Take either path, then turn to face the structure that divides the two paths, and press the monitor. This lowers, revealing a small room containing a partial invisibility and two shadows. The switch remaining in the room lowers the other monitor.
 * 5) Sector 16280: This secret can be found in the small area opposite the left entrance to secret 4. Pressing the computer panel opposite the lamp will reveal a small room containing some useful supplies, including a green armor, some stimpacks, and a box of shells. While it doesn't count towards the secret count, you can open the silver panel in the corner of this room, which contains a pony's head on a stick, which, during development, was the ZDoom forums avatar of gothic, who co-designed this region of the map.
 * 6) Sector 14557: In the security station, near the switch that raises the bridge and opens the bar blocking the way to the communication center, a wall can be lowered to access a secret room with zombie scientists, a rapid fire trooper, some ammunition and a medikit. The room can be seen through a gridded opening near the entrance to secret 5.
 * 7) Sector 1619: At the top of stairs linking the tech lab and Waste Processing, turn right to face the three pipes. Between them, you should see a switch. Shoot it to open a door behind you. This leads into a room containing some imps, a chainsaw, a box of nails, a backpack, and a data log belonging to a Dr. Samuel Oliver.
 * 8) Sector 4756: After disabling the lockdown, jump into the small opening where the flesh spawns emerge. This drops you down into a nukage tunnel, containing a box of nails and a grenade. To leave this area, use the switch to open the emergency hatch, which brings you out near the security station.
 * 9) Linedef 18840: In the corridor outside the blue key room (where the arachnotron is encountered), head to the small room marked as part of the security station. On the longest wall of machinery, press the panel with the red button and the lightning symbol. It lowers, triggering the secret, and revealing a face inside a space suit labelled "Jimmy." If you press his face, he will express his annoyance at being woken up. Pressing his face numerous more times will print messages ranging from further irritation, to shameless plugs to his projects and his website, as well as telling you that he composed the music that is currently playing, along with Icytux. Eventually, in order to get you to leave him alone, he gives you a megaarmor, then the panel raises back into place. You cannot lower it again after this.
 * 10) Sector 3428: In this same area, when you enter the service tunnel opened by the blue key terminal, look for two narrow metal supports. Press the wall between them, and go up the ladder to trigger the secret. Some shells and grenades are up here.
 * 11) Linedef 26070: Travelling to the courtyard via the hub area mentioned above makes this secret very simple to find, as you pass underneath it before you access it. Once you are outside, take an immediate right into the area between the base and the signpost. Climb the ladder to trigger the secret. Inside the building on this floor is a medikit, some shotgun shells, a rocket, and a grenade.
 * 12) Sector 9944: From secret 11, head across the courtyard to the blue door, marked as the Networking Hub. Turn right, and as you turn the corner in this small passageway, look for the small crack in the inside wall. Inside is a red light. Shoot it, and you will see a passageway open on the right of your screen. Enter the passageway and drop down the hole to trigger the secret. You are taken to a small cavern overlooking the courtyard, which contains a computer area map, and a data log containing the second excerpt of Dr. Acheron's "Project Babel," where Acheron suggests that he may have to try and find the origin of the demon species himself. Before you shoot the switch, take note of the red door on your left, you will need to remember its location for later (see secret 12)
 * 13) Sector 3332: Where you find secret 10, you should be able to see a green UAC hologram on the roof of a grey structure, and a lift leading to it. Go up the lift, and look for the ledge on the right with the palm tree and health bonuses arranged in a square. You will need to jump and possibly straferun to get to it, but you will trigger the secret when you land on it. On ITYTD and HNTR, the square is made up on 51 health bonuses. On HMP, there are 34, and 17 on UV.
 * 14) Sector 1690: Heading towards the simulation room, you will cross a bridge over a lagoon. At the far end of the bridge you will see a metal support just to the left. Jump down on to the ledge it is placed on, and move around the building on this ledge. Jump up onto the ledge where the rapid fire trooper is/was located. This will trigger the secret, and you can take a box of ammo and a stimpack from here.
 * 15) Sector 1691: In the middle of the courtyard, you should find a rocky archway. On HMP and UV, you can find a Mancubus standing beneath it. When you get here, turn towards the northern rock wall and find a small ledge you can jump up onto. Continue to jump up the ledge and you can drop down into a small tunnel, where you find a box of frag grenades. Continue along this tunnel and you will come out on the chaingunner's ledge overlooking the lagoon, where you can find a box of bullets and a stimpack. You will need to step out onto the ledge to trigger the secret.
 * 16) Sector 3315: In the central junction, note that inset panels with a warping green liquid behind it. On the north wall in the north-east corner, look for a narrow section where the liquid is blue instead. Press it, then head to the eastern door. Crouch under it and head into the dark tunnel. This triggers the secret, which contains only a health bonus. Venture as far in to the darkness as possible, and message will appear on the screen. It reads: "Well done, Marine. I certainly look forward to seeing you aboard Cybergaze 2.1x..." This message is a reference to Insanity's Edge, a 1.5 map GZDoom modification by Pyroscourge, who designed the central junction. Just outside the secret is a data log belonging to Geotechnical Engineer Zarby.
 * 17) Linedef 61111: This is, without question, the hardest secret in the level. When you were accessing secret 10, you would have seen a red door. If you return here with the red key and go through that door, press the switch and you will find a small room overlooking the courtyard entrance to the central junction. This takes you to another small room, apparently isolated from the map. Amongst your supplies, you find another data log belonging to First Technician Paddock, who had fixed the keypad on the wall in front of you, which opens the adjacent door. According to Paddock's log, this door leads to Dr. Acheron's private bathroom, and he couldn't understand why it was locked. Remember how to get to this area. On your way to specimen control, after you pass the red door, on your left is a switch. Pressing it will open a white teleporter in front of you, and four coloured ones behind. These colours are red, blue, green, yellow. As these open, the panels to the side of the white teleporter will begin to light up with each bar one of the four colours. These colours are as follows: Blue, yellow, red, green, yellow, green, blue, red, red, yellow, blue, green. If you take the wrong teleporter, you are taken to a hellish version of the watchtower, where you can find the data log of Cpl R. Todhunter. This room contains four teleporters, each with a chaingunner stood on it. Kill one then quickly use its teleporter to escape, as another will spawn in soon after. Taking the correct teleporter will take you to the real watchtower, where the four teleporters are seen behind bars. You will need to kill all monsters to open the door, then take the next correct teleporter. Making a mistake will drop you back in the helltower, and you will need to start again, though any killed monsters will not return. Each time you take the correct teleporter, the room reset, and a new bar lights up in the watchtower, showing your progress. You also encounter tougher monsters, and better supplies to help you tackle them. This eventually culminates in a final battle against three cybruisers. The final teleporter takes you to a dark room, where you see four numbers painted in blood on the wall. These numbers are the security code for Dr. Acheron's bathroom, and are randomly generated at the start of the level via a script. Memorise them or write them down, then go back through the teleporter. Take the megasphere and return to the room with the keypad. Enter the code, and the door opens, triggering the secret. Inside is the map's one and only BFG9000.
 * 18) Sector 16421: When you take the megasphere after completing the watchtower secret, pressing the switch that opens the bars also opens the door immediately on the right when you enter specimen containment. Inside are some backpacks, a box of grenades, and a green armour.
 * 19) Sector 4753: After you tackle the first angel, go through the teleporter to the next area. Go around to the side of the weapon lab building and look for a ladder. Climb it, and retrieve the megaarmour in the corner.
 * 20) Sector 7752: Now inside the entrance room to the weapon lab, go to the box with the tech pillar on top of it, and look for a switch on the side. Press it, then leave the room and go back to where you entered this area. Stay on the ground level, and go to the side of that structure, and enter the teleporter there. This takes you behind the specimen containment area, and among some pinkies, you can find a soulsphere, and some rockets.
 * 21) Sector 10751: After the red door, just after you enter the caverns, keep an eye out on your right for a crucified dark imp. You can jump up the terrain to get to this. Behind the cross is a napalm tank.
 * 22) Sector 5195: In the eastern complex's research annex, a balcony full of chaingunners can be reached with good timing by strafe-jumping into it and crouching while in flight. Inside are some grenades, a backpack, and the heavy weapon zombies' dropped chainguns.
 * 23) Sector 5196: In the same area as secret 22, just before the door to dark claw's containment room, a wall on the west side can be lowered to access a small niche with a soulsphere.
 * 24) Thing 1971: In Hell, after going through the majestic entrance hall and just before entering the tunnels of blood, this berserk pack can be obtained by lowering the bars preventing access. This is done by going through a wall on the other side of the room, navigating a short interrogation mark-shaped corridor, and attacking a mouthed skin wall.
 * 25) Sector 5457: This secret requires the blue skull key to access it, found in the eastern complex's research annex. In Hell, reaching for the dark claw in the courtyard triggers an ambush by unleashing bruiser demons and Hell warriors. North of the fiends' closet is a blue-skull door guarding the secret room with the mighty soulrender.
 * 26) Sector 7628: As you turn to go down the final flight of steps leading to the bridge to the boss area (look for the dead marine), on the corner, jump over the side of the walkway, and you should land on a small ledge where you will see a sign saying "Xaser's Amazing Weapon Modification Station!" As you enter, the secret will trigger and upon entering the room itself, a message appears on the screen instructing you to place a weapon on the station to have it modified. Attempting to use the station will place the normal shotgun on the station, where it will lower out of the sight. After a few seconds it will return, this time as an AA-12 automatic shotgun, which has a much higher rate of fire. Go back out on to the ledge and press the wall of skulls to get back onto the walkway.

Easter eggs
The map is full of hidden Easter eggs and "signatures" which are not always marked as secrets. Some of them include:
 * The Hitlercube: In the area of secret #1, jumping while looking to the south-east on the shore may allow to see a small cube textured with &mdash; the Wolfenstein 3D texture representing Hitler's portrait. Shooting a hitscan weapon at the Hitlercube will result in a demonic roar, a music change, and a displayed message. Both the music and the message are taken from TurboCharged Arcade!.
 * Half-Life room: Accessed from secret #3. A recreation of the Sector C suit room. The HEV suit is replaced by a radsuit (the only radsuit of the entire level). There is also a crowbar (that, unfortunately, cannot be picked up and used) and a data log belonging to Gordon Freeman, with a silent record.
 * Cran World: While escaping from Hell, near the end, there is an area with two ledges separated by lava, and a small bridge on the south allowing to cross safely. Once on the other side, go to the north until you find three grenades at the tip. From here, you can jump down to a small, barely visible triangular platform below (it is advised to safe first, as the jump is easy to miss). A small corridor in the rock leads to an oddly-located tech room with a computer console decorated with a . Activating the console opens the way to the capital city of the USA. One of the golden logbooks can be found here. A switch behind the White House teleports back to the ledge, at the place where the three grenades were.

Things
The level contains the following number of things on each skill level. Does not yet account for Thing_Spawn. Custom things are italicised.

Development team

 * Alex Meyers (Apothem) - Scripting
 * Blue Shadow - Testing, support
 * Captain Toenail - Mapping, coding
 * Chronoseth - Mapping
 * Deathknight - Testing, quality control
 * dj-jo - Music
 * DTDSphere - Mapping
 * Dusk - Mapping, coding, textures
 * Gez - Mapping, quality control, textures
 * Ghastly - Coding, quality control
 * gothic - Mapping
 * Grymmoire - Mapping
 * Henri Vuortenvirta (Icytux) - Music
 * Infirnex - Mapping
 * James Paddock (Jimmy) - Mapping, music
 * Chris Kassap (lupinx-kassman) - Mapping
 * Andrew Rehberger (Malinku) - Mapping
 * James Cresswell (Phobus) - Mapping, quality control
 * Pyroscourge - Mapping
 * ShadesMaster - Mapping
 * Fraser Low (TheDarkArchon) - Mapping, coding
 * Daniel Gimmer (Tormentor667) - Project lead, mapping, graphics, textures
 * Björn Ostmann (Vader) - Mapping, graphics
 * Xaser - Mapping, coding, quality control, music
 * zrrion the insect - Mapping