Switch to electrical view, select your pistol and fall to the floor. When you've killed all the aliens, use your grappling hook to pull yourself up to the ceiling, then into the tunnel. Make your way up the tunnel and out into the large room with the alien statute. Dispose of the facehuggers on the floor, then head down the tunnel in the corner of the room (where the blood trail leads). Head down this tunnel and fall down to the floor. This bit's tricky. You need to attach the grappling hook as high up on the wall as you can, then when you fly up in the air quickly press the grappling hook key twice to attach it to an even higher spot. Repeat the process until you reach the top. Follow the blood trail up and into a room with loads of pillars on their side. Head into the tunnel in the far left corner. When you emerge in the next room, ride the lift in the far right corner up. Head down the tunnel, then in the next room ride the lift on the left up. Go around the ledge and into the next room. Ride the lift up re too. You'll emerge in an enormous room, offering four ways to go. Surprisingly enough, you want to go neither. Instead, stand at the bottom of one of the four sets of steps, and look up. There's a hole in the ceiling, and you need to pull yourself up there. Once you're there, you need to worm your way through the gap in the centre to get on top of the half-pyramid and into the long, thin chimney-like thing. Once you're in there, you need to do the process of hooking, waiting until you're high up in mid-air, then hooking again. There's a very large room halfway up, but you actually need to go higher up, up through the next chimney-like thing. When you reach the top, there are two "ramps", one either side of you. Behind one of them is a tunnel that you should be able to see. Get into that tunnel. Then, fall to the floor and take out the two Praetorians. Once you've done that, pull yourself back up into the tunnel, go over the ramp and down the chimney-like thing but get yourself into the room halfway down. w head through the arches on one side of the room and fall down the hole. This takes you into the facehugger shrine. Head up the tunnel and into the room to end the level