MAP25: Unstable Journey (BTSX-E2)

MAP25: Unstable Journey is the twenty-fifth and penultimate map of the second episode of Back to Saturn X. It was designed by Brett Harrell (Mechadon) and uses the music track "Weather Warning," composed by James Paddock (Jimmy).

Essentials
The three keys can be collected in any order.

Yellow key
Press the button in front of you to lower the wall, revealing a shotgun and chaingun, then head straight forward past four imps (or shotgun guys on Hurt Me Plenty (HMP) skill level or higher) to a door. Open the door to confront one or two demons and some zombiemen, then go straight forward to a crescent-shaped room with some imps - this is where you can exit the level once you have all three keys. Leave the room through the east doorway to get to an outside yard; a pillar holding a rocket launcher will lower, along with the east wall which conceals cacodemons, demons and shotgun guys (or chaingunners on HMP or higher). Go down the steps behind the wall and drop down the holes to your left or right, then follow the passage to a pair of doors that have a super shotgun and a switch between them; pulling the switch will raise steps leading back to the previous area, which you will need later, but will also trigger an ambush by two revenants and/or arch-viles.

Open either door and kill some waiting demons, then open a second door to the left and go up some steps to dispose of imps. Open the door at the top of the steps and kill more imps along with two mancubi (plus two revenants on HMP or higher), then open another door in the north wall and turn left to see a crucifix button - it will disappear when pressed, revealing two platforms you can cross to drop into a pit where demons will teleport in (you will also see four chaingunners on HMP, or four revenants on Ultra-Violence (UV) and Nightmare (NM)). Pass through the door at the south end (which will seal behind you) and kill some more imps, then go to the west side of the room to trigger an ambush by mancubi, demons and zombies. Pass through the left-hand door in the north wall and fight your way round the next room to some steps, then go up to see a plasma gun in front of a diamond button; pressing the button will lower the column in the center of the room and eventually reveal the yellow skull key, but you will have to fight off a crowd of demons and other monsters while you wait.

Blue key
From the yellow key, leave the room through the south door then go back to the pit and press the crucifix button on the north wall, which will lower two lifts holding demons (or Hell knights on HMP or higher). Step past the lifts to a set of yellow bars and open them, then head up the steps, ready for an ambush by imps and cacodemons, and open the door at the top to return to the corridor with the two platforms. Head south through another door and continue in that direction until you see a door on your left bordered by blue tiles, then pass through it and climb some steps to a room with imps and zombies. Enter the neighboring chamber, which has a blue floor, then turn left to see one to three knights guarding a crucifix button - pressing it will lower a pillar holding the blue skull key, visible through the nearby grate.

Leave the chamber and walk east, past a bookcase that has lowered, to a room with some imps, shotgun guys and zombiemen (or chaingunners and revenants on HMP or higher), then walk north down some steps to a room with some red flesh. Head west down a second flight of steps then turn left to see the blue key ahead; taking it will cause demons to teleport from the flame wall in front of you, along with cacodemons in the flesh room and an arch-vile on the upper floor.

Red key
With the blue key, go back to the yard that had the rocket launcher and head south to a curved wooden wall with red strips, then press the diamond button opposite that wall to lower it and reveal some demons and cacodemons. Drop down the hole in the south-west corner and open the door here to confront two cacodemons guarding a super shotgun, then enter the adjoining chamber to the north to find some imps guarding a diamond button. Press that button then go back to the previous room to see that barriers have lowered, letting you enter an area with armor bonuses, boxes of rockets and a megasphere (or supercharge on UV and NM). Kill the cacodemons and lost souls (or pain elementals on HMP or higher) that teleport in then press the crucifix button, then head east along a dark hallway to a marble room with mancubi and one or two arachnotrons. Head south-east past a large column, noting any revenants that are released to your right, then press a crucifix button at the end of the room to lower a barrier with a computer area map as well as some bars to your right.

Pass the bars and turn right, then follow the path past three knights (or barons of Hell on UV and NM) to a tunnel with some demons. Continue south until you pass an arachnotron and more demons, then look for some steps on your right and climb them; there are shotgun guys, imps and demons waiting at the top, and up to five mancubi will appear through the fence once you enter the main room. Press the crucifix button on the east wall to reveal a plasma gun behind you, then go back down the steps and deal with some demons and cacodemons before continuing south to a lava pool. Cross the pool to reach a clearing with some more arachnotrons, then go down the south-west steps to reach a brick tower. Climb to the top to find two revenants guarding a crucifix button, press it to enter the tower and deal with some imps and cacodemons, then press a second button to lower a megaarmor as well as a barrier blocking the way forward. Head east past one or two knights to a diamond button and press it to lower the walls on either side, then step through and pass some cacodemons to reach a door. Open the door and head past some shotgun guys to a second door, which has a teleporter behind it.

Enter the teleporter to find yourself in front of another tower guarded by imps and cacodemons, then go inside it and press the crucifix button in the center to lower the column with the red skull key by one level. Go back to the teleporter and use it to return to the previous room, where a second teleporter has opened in the south-east corner; this teleporter will send you to a second crucifix switch in the tower that will lower the column again. Step backwards to return to the room again, then use the third teleporter that has opened in the north-east corner to reach a ledge on the east side of the tower that holds a supercharge (or a megasphere on UV and NM, joined by an invulnerability on I'm Too Young To Die and Hey Not Too Rough); as you step off this ledge the red key will lower to the floor so you can collect it. Doing so will cause a crowd of enemies to teleport outside, including one cyberdemon on HMP or two cyberdemons and an arch-vile on UV and NM; fight them off them go to the north-west corner to see that a crucifix button has been revealed that will lower a lift next to it, allowing you to escape.

After using the lift, follow the red steps up to get back to the clearing, then head east until you reach a fence which has large ammo pickups next to it; now head north-west into a building where you will see two red key doors. Open the north-east door, which is guarded by two knights, to enter an enclosure with a couple of mancubi, then open the west door and step through it before turning round to kill some chaingunners that are revealed behind you (plus an arch-vile on HMP or higher). Go past those chaingunners and approach the lava-fall ahead, which will lower to reveal an arachnotron, then press the diamond button behind it before returning to the door you opened earlier. Step through and kill some cacodemons and revenants that have teleported into the next room, then enter the teleporter at the back of the room to reach a nearby ledge with a partial invisibility; there is a diamond button behind you that will lower the walls on either side, leading back to the area where you found the computer area map.

Go down the steps and straight forward to a bailey that contains a spiderdemon, or two on HMP or higher. Activate the lift at the north end of the bailey and ride it up, open the door on your left to confront a cacodemon then step round the bookcase to lower a wall ahead, revealing another room with cacodemons, shotgun guys and one or two knights who are protecting a super shotgun. Press the crucifix button in the south-west corner to lower some steps, then climb them to return to the yard near the starting point.

Exit
With all three keys, go back to the crescent-shaped room in the north-west corner of the map and open the colored barriers here, then step through to collect a BFG9000 and megasphere (or a supercharge and megaarmor on UV and NM) as well as some energy cells. Go down the steps to a diamond button and press it, which will lower the wall but also cause various monsters, including arch-viles on HMP or higher, to appear on the steps. Once the wall has lowered, enter the flames behind it to finish the level.

Official

 * 1) From the map start, the wall to the left of the door has a different decal. This is a switch that will lower a wall to the left when you exit the starting room, revealing a staircase to a platform with six imps, a berserk pack and a backpack. The little room at the end with the plasma gun and some energy cells (sector 1860) counts as the secret. In case you miss the hidden switch at the start, you can still access this by opening the small chute in the small courtyard the secret overlooks (it requires the blue key) and use the switch behind it to lower a lift to the platform.
 * 2) On the path to the yellow key (north-central part of the map), there is a zone where you need to walk across two pillars then drop into a hole. After dropping into the hole, there is a nearby lift with a backpack on top. The eastern wall on that area has blood marks on the bottom; press on it to find a passage (sector 1781) leading to five chaingunners and a supercharge.
 * 3) In the small maze that leads to a red room with a BFG9000 on the north-eastern part of the map, the engraved wall without the horizontal bands on the eastern part of the maze can be lowered, allowing you onto a ledge (sector 1592) with some boxes of rockets and a few shotgun guys. From here you can drop down to an energy cell pack.
 * 4) Around the center of the map and beyond the blue key door, if you ride up the lift in the bailey with the spiderdemon, you will find an extended gauntlet that leads to the computer area map. Immediately before the green-floored room with the map is a very dark passage with two thin pillars, with spectres in alcoves left and right. Press on the blinking pentagram figure at the end of that passage to open some walls in the room with the map to reveal a secret area (sector 1140) where you can jump off to collect, depending on the difficulty, either an invulnerability or a megaarmor.
 * 5) On the path to the red key, in the center-west part of the map, there is a zone where a megasphere can be observed on a pedestal up in the rocks. Nearby is an elevator which can be used to access a small room containing a berserk pack. Pressing on the pentagram-inscribed wall there will lower it and reveal a passage (sector 1428) with an arch-vile, a set of shotgun shells, two energy cells and a clip. There is also a thin window through which you can see a diamond button across the gap.
 * 6) Shoot the button visible from secret #5 to remove the lower lip of the window, then drop down through it and make a U-turn to the left. The switch has also opened a large rocky section of the map which eventually leads to the pedestal with the megasphere (sector 1204) on the rocky wall.
 * 7) On the path to the red key, in the center-west part of the map, there is a section with lava-falls that create a pool of lava with two big stepping stones. From the rocky section with stairs immediately following this section, there is a path to an elevated level where you can get a panorama of the lava pool. From there, look west and you'll see an evil eye. Jump off to the rock ledges to its left and follow them towards the eye to reach a cache (sector 413) of three energy cell packs behind a twisted tree.
 * 8) After getting the red key and surviving the ambush, ride the lift out of the arena to the top, and from there you can drop to a small ledge close to the evil eye (sector 951) and collect an energy cell pack.

Non-official

 * To the west of the red room with a BFG9000 in the north-eastern part of the map, there is a room with a megaarmor, supercharge, boxes of rockets and energy cell packs and a pulsating "LOL" on the floor. This room is behind a false wall over the bookcase with the blue torch in the north-west corner of the red room - the wall can be identified by the lack of a skull decal on the wall. The only way this can be reached legally is with a chained arch-vile jump during the BFG ambush.

Current records
The records for the map at the Doom Speed Demo Archive are:

The (absence of) data was last verified in its entirety on February 21, 2022.

Player spawns
This level contains seventeen spawn points:
 * 1) facing north-east. (thing 2421)
 * 2) facing north-west. (thing 2422)
 * 3) facing north-east. (thing 2423)
 * 4) facing south. (thing 2424)
 * 5) facing west. (thing 2425)
 * 6) facing south. (thing 2426)
 * 7) facing south. (thing 2427)
 * 8) facing south-west. (thing 2428)
 * 9) facing west. (thing 2429)
 * 10) facing south-west. (thing 2430)
 * 11) facing south-west. (thing 2431)
 * 12) facing west. (thing 2432)
 * 13) facing south. (thing 2433)
 * 14) facing east. (thing 2434)
 * 15) facing north-east. (thing 2435)
 * 16) facing south. (thing 2436)
 * 17) facing north-west. (thing 2437)

Things
This level contains the following numbers of things per skill level: