Mars City: Union Aerospace Corporate Division/Walkthrough

This is a detailed walkthrough for Mars City: Union Aerospace Corporate Division. Your mission is to return to Marine Command for a status update from Sergeant Kelly, then join up with Bravo Team in the Alpha Labs Sector.

Linking up with Sarge
While you were down below in the Underground, things have changed in Mars City. The populated rooms are now filled with demons and the people working there turned into zombies. You must traverse both already explored areas and new parts of the level, with items that you probably saw before.

You start the level in the elevator. Exit into Maintenance after you get a new objective, then shoot the Pistol Z-Sec that appears from behind the crates while steam comes out, obscuring your vision. Unfortunately, even if you haven't picked up the Bullets in Locker 001 they will no longer be there, so get the Pistol dropped from the Z-sec. There is also your first secret in this room, so jump up on the railing then onto the broken steps on a platform with a dead marine, a Machine gun and three Armor Shards. Unfortunately the door is broken so you will have to go up the ladder.

In the Ventilation Shaft you will encounter your first survivor, R. Roland. He does not want to come with you, so you can either kill him or leave him alone. In the vents, the path to the right is blocked by some pipes, but after you go to the right of the Security Armor which you should pick up they will blow up so you can pass.

Drop down into Manifest Control Office on an opened panel, try to advance then immediately turn back: another panel will go down revealing a Zombie. Kill him quickly then get the 2 Armor Shards that were in his closet. There is another zombie in this room, so watch out. Pick up Marcus Stanton's PDA from the table then crouch below the fire to get 2 Armor Shards. There is also a Large Medkit on a box near the door.

Once you enter the Manifest Control Entrance one Shotgun Z-Sec and one Machine Gun Z-Sec will pop out from the door in front of you. Be sure to collect the ammo from them. You can also hear a Pistol Z-Sec from behind the locked ACO door, giving you your next objective. Reception Processing is open, however. Inside you will get a small scare from an Imp eating a fat Zombie. Pick up the 2 Small Clips and the ACO Keycard that are on the table, then exit the room.

Use the newly acquired key on the previously locked door. Inside the Conference Room there are 2 Pistol Z-Secs and a Small Medkit. If you look out the window you will see a Sentry Bot fighting more Z-Secs. Again, don't forget the dropped ammo. Enter the Hallway and then Sec Ops Processing, then immediately backtrack as a Zombie will spawn way back in Manifest Control Entrance and is going to surprise you. After you kill him, get back where you were before where you will encounter 4 Zombies. In the dark on your left there is a Small Clip and 5 Armor Shards. In the same corner of the room there is another Small Clip and Small Shells. This is also the first place in the game where you could choose between two rooms.

If you enter Security Operations you will encounter a Machine Gun Z-Sec and a Pistol Z-Sec. Pick up their ammo and a Small Medkit then return. Go to the Sec Ops Junction, where you will find a person on a video call getting attacked by an Imp. On the crate to your left is a Large Medkit, and behind it is a Large Clip. A flaming Zombie will emerge from behind a fiery pipe. There is nothing behind it, so move on.

Immediately after entering Infirmary Access Junction kill the Machine Gun Z-Sec in front of the door, the Pistol Z-Sec behind the tanks and the Shotgun Z-Sec that is coming from the right. After killing all of them also shoot your first fat Zombie on your left which has 5 Armor Shards behind him. Once you turn right an Imp will drop down from a ceiling and presumably the same Imp that killed the person on the video call will also pop out of the Operation Station, which has a Small Clip on a box.. In the same room that you were before, behind the tanks, there are 2 Armor Shards, which I recommend not picking up, because by doing so another Imp will leap towards you. If you haven't entered Security Operations then backtrack to Sec Ops Junction, where a Machine Gun Z-Sec will come out of the door.

After that intense fight in the last room you will finally get a breather in the Infirmary. Inside you will find a Health Station, a locker and Mark Caseon's PDA, which is the disturbed doctor that you found in the beginning of the game. In the locker there is a Security Armor, a Large Medkit, a Small Clip and two Small Shells. Once you open the door to the Infirmary Observation Room you will get attacked by the Zombie that you saw being put on the table in the first level. If 2 Machine Gun Z-Secs haven't spawned, re-enter the room. There is an Adrenaline on the other operating table and a Large Medkit on a shelf. In Marine Command a flaming zombie will come from behind a fire. Crouch down beneath it to find a Small Medkit, Small Shells and two Bullets. Further from those there is a dead marine (presumably Bill Tyson) and his PDA. Go back and crouch beneath the pipe again. Going the other way there is a Zombie strangling a marine. Dispatch him and progress further into Marine Headquarters. You will hear a voice repeatedly saying "Video link-up requested". Pick up a Machine Gun from the ground and a Large Clip from the comm center table, then wait for further orders from Sarge.

Catching up with Bravo Team
After your PDA got updated for the Administration Clearance, enter Combat Preparation, with a Pistol Z-Sec Inside. On the other side of the code locked door there are 2 Shotguns, 2 Large Clips, 1 Security Armor, 2 Machine Guns, 1 Small Shells and a Large Medkit. Backtrack to the entrance of the Infirmary Observation Room, where 2 Machine Gun Z-Secs will have spawned. You can now safely backtrack to Security Operations if you want to.

Enter the Office Access door that leads you to Marine Command Access, where the door will be blasted off if you haven't killed the 2 Z-secs that were there, now emerging out of Security Operations. If you enter it now, another Machine Gun Z-Sec will spawn from the other side. If you have killed them before, you will encounter another Machine Gun Z-Sec on your left. A zombie spawns there regardless, along with a Large Medkit.

Command Access Junction is a tough spot: a Pistol Z-Sec will come out from the Common Area, along with a Machine Gun Z-Sec. Once you kill both of them, another Pistol Z-Sec will appear from the Restroom. Enter the kitchen, where you will find Small Shells on the counter, along with 7 Armor Shards. A Zombie with a flashlight will come from the broken Super Turbo Turkey Puncher 3 arcade. You can also find a Small Medkit there. After receiving the transmission from Sergeant Kelly about the Sentry Bots which you have seen before, a Pistol Z-Sec and a Machine Gun Z-Sec will come from the hallway. Entering the Restroom is optional: there are only 4 Armor Shards there, but after getting jumpscared by yourself from the mirror, an Imp will spawn outside. Regardless if you enter it or not, a Shotgun Z-Sec will be waiting for you at the end of the hallway.

You will finally be able to fight alongside a Sentry Bot in Central Access, with a Machine Gun Z-Sec as your first target. Do not enter where he came from though, so continue to the Mars City Reception, where you saw the Imp eating a fat Zombie, the Zombie being still here. The second secret is behind a locked door, so jump over the window and get a Large Clip, a Large Medkit and a Security Armor. Backtrack to where you got attacked by the Z-Sec. In the ACO Access Junction you will find a Machine Gun Z-Sec right in front of you, another one behind the corner and a Shotgun Z-Sec behind the railing. Another two Machine Gun Z-Secs will come for you, while another one is in an office with a Large Medkit. The last one is hiding behind a pillar, so be prepared for him coming out. There are a few supplies here, but we will come for them soon. The moment you enter the ACO Lift Junction you will be attacked by two Machine Gun Z-Secs on your right, in the shadows. An Imp will throw a barrel at you and another one will come from your left. Another 2 Imps will come from behind you, but sometimes they glitch out and don't spawn. The Sentry Bot will also shut down here. The third secret is in an open vent on your right: crawl in it and go up the ladder. You are now on the balcony which the Imp that was throwing the barrel was on. Here you can find 3 Armor shards and Small Shells, but also Duncan Mathews' PDA, which updates your security clearance to Analyst Office. Backtrack to the locked door that your newly acquired PDA can open. Inside you will find the last enemy in this level, a Zombie. On the office tables there is a Large Medkit, a Large Clip and a Security Armor. Backtrack further to the room with the railing and the dead Shotgun Z-Sec where you will find a Small Medkit behind a box and Small Shells. You have now gotten every item and killed every enemy in this level, so you can enter the elevator and go to the next level.

Notes and Author's Thoughts
This level introduces enemies that only spawn when backtracking.

The enemy count is the same whenever you choose to go to Security Operations or not.

Should multiple Z-Secs be called Z-Sex? It's shorter.

This is my first page on a wiki ever, so Quasar be gentle. Also please link to the main Mars City page as I don't know how to do that yet. I will also do 2 separate walkthroughs which should be more complete than Woopzilla's, featuring both entering Security Ops early or not.

All item info is taken from my thread |here|