Head out the room via the door, then head through the lab and out into the main corridor. Walk up the corridor a bit and you should find a Predator blood trail on the floor. Follow it left and keep on it until you come to a large door that opens to reveal a similarly large room. From here head right and down the stairs to enter engineering. Shoot the barrel-like things in front of you (you only need to shoot one of them) and then quickly dash into the room on the right and do the same thing. The self-destruct sequence stops. Now return to the large room and follow the Predator blood trail again, this time all the way down the corridor and into one of the labs. In this room is a Minigun. Collect it, then follow the Predator blood trail back again to the large room. Now kill the Predator with said Minigun. When it's dead, turn around and make your way back down the corridor, then head left when it splits. Continue down it and eventually you should find yourself in a control room, then head up two sets of steps enter the airlock. Pass through it, then ride the lift down on the other side (it should kill the facehugger). Continue across the room and into the corridor at the other end. Head right, down the corridor and follow it round the corner. Go further down and there's an operation room on your left. After that there is a tunnel, then another operation room. Proceed down the tunnel. You emerge in a long, tall corridor. Make your way up it, then at the end take a left and turn left again. There's a door in front of you. I'd strongly recommend that you save it now. What follows is a series of many, many containment rooms, but all the aliens have been released. Make your way through all the rooms, killing as many aliens as possible, but concentrate on actually running - the more you stick around the more aliens will turn up. Run through all the rooms, then you'll reach some stairs with an airlock at the top. Enter the airlock, then turn around and kill any aliens still chasing you. On your right should be a lever. Pull it and the second airlock door will open. On the other side is a sentry gun, so once you reach this point you are (reasonably) safe. Right, now for the final part. You're in an area that houses the security mainframes - it helps if you know the level having played it from the Predator's point of view. There's a lab in the middle and four rooms around the edge each with a mainframe in them. You need to explore all the rooms and kill the aliens you find. There's normally about four. There's also a lone marine with a pistol that represents a company head - if he dies, you fail the mission. When you kill the final alien, the level ends