Exit the lift into the lobby and a cut scene will play. Head left and kill the z-sec and the zombie sat on the bench. Head through the door and take out the imp, another couple of z-secs and a zombie. Take the first door on the right for some pick ups and Alan Dorweiler’s PDA. Check the PDA to find the code for the locker and more goodies (586). Head back out and take the next door which has a sign saying Alpha Labs above it where an imp will jump on you. Through the window of the next room you’ll see an imp throwing fireballs at you and then you’ll meet a fallen marine called E. Webb who you can talk to. You can’t get through the next door so you’ll have to go back and find the PDA of William Banks. Head back to the lobby where you got off the lift. Two imps will smash through a door and attack you – kill them and enter the room.
You’ll be attacked by another couple of imps inside but there should also be a medkit in the corner. Head through the door and take out the z-sec. There’ll be more enemies, another z-sec and an imp then another door. On your right there’s a room; enter it and activate the security override on the screen at the end. This will trigger a cut scene.
Take out the pinky as he waddles towards you and exit through the opening taking the door on the right. You’ll have to kill an imp, then head up the stairs and take out another imp, a z-sec and a pinky. Continue and you’ll find Jonathan Moses’ PDA which prompts you to visit the Martian Buddy website to get the code 0508 which will let you access the locker and get the chaingun.
Head up the stairs and you’ll get a radio transmission from Sgt. Kelly. Enter the corridor on your right and kill the imp and zombie before going through another door to find a z-sec. There’s a zombie behind the next door and some armor in the alcove on your left. You can find William Banks’ office on the right where you’ll find ammo and a medkit but no PDA.
Head to the other office with candles in it and you can find the PDA on the floor. Watch out for the imps that spawn in and then go back, down the stairs and into the lobby, again killing more imps along the way. You now have access to a previously locked door and you can enter the room from the cut scene at the beginning of the level. You should find a PDA belonging to Paul Simon. Now you can go back to the Transfer bay where E. Webb was and use the control panel to enter the lab.