Creating a LadderAt the beginning of the level you will be dropping. Press the action button to grab the first ledge and slow your fall. Let go and press the action button again to grab hold of the passage. Pull up and collect the shotgun ammo. Drop into the pool. Climb out of the water and follow the passage. Run up the stairs. Shoot the window on the right and collect the crystal. Climb up the ladder. Climb further up. Run ahead and into the passage. Pull the crate once. Then take a look around the chamber and pick up the flares, some shotgun ammo and some Uzi ammo. Run to the other side again kill the Damned on the right. Carefully drop through the opening in the middle. If possible, shoot another Damned from up here. Turn towards the single ticket booth and jump there. Walk towards the edge. Jump up and hold on to the ladder, which you created with the crate. Climb up.
Maintenance KeyLower yourself backwards into the other opening to land in a passage behind the crate. Follow it. Climb down at the end. And drop into the chamber. Pick up the maintenance key as well as the large medipack on the window sill. Use the switch to open the door. Kill the Damned if you haven't done so from the ticket booth. Pick up the small medipack he has lost. Step outside. On the right side is only a passage leading back to the pool.
Room With CratesTurn left. There are four passages. The left two lead to the left escalator and the two on the right to the right one. Step into one of the right passages. Run down the escalator. Lower yourself onto the track. Look down in both directions. One side is lit in red, the other is blue. Run into the direction of the blue light and quickly jump into the doorway on the right before the underground hits you. Run up the ramp and kill the two Damned. Pick up the small medipack in a corner. Climb onto the stacks on the side of the ramp. Collect the crystal. Climb back onto the previous crate. Kill a dog, which appears in the chamber. From this crate, make a sideflip onto the sloped block. Hold down the jump button and press the action button to grab the ladder. Climb up. Leave it with a backflip onto the platform behind you. Kill the Damned on the stack of crates behind you. Collect the small medipack. (Above the crate on the right is a closed trapdoor.)
Go towards the crate in the right corner, but don't climb up yet. Turn right and jump onto the platform there. Look over to the right. You have to jump into the alcove behind the ladder. Collect the Uzi ammo or the Uzis itself. Jump back the way you came and grab the ledge. Pull up. Return to the platform behind the ladder.
Drill ShaftSlide down and climb up to the right. Turn around and standing jump towards the niche. Pull up and collect the rockets. Climb onto the lower crate again. Step forward. Picture: You can see a giant drill on the ceiling. In the wall ahead just underneath the drill, on the left, you can see a gap, there is the first Solomon's Key. But you cannot reach it, as long as the drill is here. Slide backwards down the ramp. Press action to grab the ledge. Let go and quickly grab the lower ledge. Drop onto the collapsing floor tiles. Make a sideflip to the left and jump forward. Grab the ledge.
Collect the large medipack at the end of the ramp. Run back up. Climb onto the box on the left. Turn around and make a standing jump up to the ledge. Climb up again.
Fire EmittersClimb up into a shaft with a small pool. Jump into the long passage and collect the crystal. Get back towards the grating and climb up. Pull up. As long as you don't take a step forward, the fire can't harm you. Side step to the right. (If you want to make sure, you do not step into the fire you can also hang from the ledge and shimmy right, then pull up there.) Make a standing jump forward when the fire goes out. Run ahead and climb up onto the block. Pick up the small medipack. Climb up to the left and follow the ramp. Stand on the right wall and turn left. Make a standing jump and grab the ladder. Climb up. After a few steps, leave the ladder with a backflip. Use the switch in the alcove to open the trapdoor in the Crate Room. Then jump back onto the ladder and pull up. Wait for the fire to go out, then crouch to collect the uzi ammo. Stay down till the fire goes out. Drop down on the other side. Follow the passage to the left and into a room with a metal grating on the floor. Turn left and kill a rat. Pick up the large medipack in the left corner.
Old PennyDrop down through the opening and kill the Damned and the dog. Run between the pillars to the other side of the platform. Turn right. On the right side, you will find a door lock. Use the maintenance key. Step into the chamber and light a flare. Collect the uzi ammo, the small medipack and flip the switch in the alcove at the back to turn on the light outside. Get back out. Run along the platform. In front of a sweets-machine on the left, you can find an Old Penny.
On Top of the DrillReturn to the other platform and drop onto the track again. (As you might have noticed, you are just opposite the right escalator.) Again, run into the direction of the blue-lit tunnel and jump into the chamber on the right. Climb the ladder again. Monkey climb over to the right and follow the passage once more. Run out onto the drill and climb into the passage on the left. Picture! Collect the Solomon's Key. Follow the passage and climb up. Run to the top and drop down on the other side. You are back in the chamber where you killed the rat and found the large medipack. Drop down again.
Finding the 2 SwitchesOnce more, drop onto the track and run into the stack room again. Climb up the ladder and this time climb up through the trapdoor you have opened. Climb out. Turn around and jump into the window. Crouch. Collect the shotgun ammo. Run out and kill the Damned with his dog. Run into the chamber between the stairs. Collect the MP5-Clips. Drop through the collapsing floor. Pull the crate out once. The other trapdoor drops down. Climb back up and down into the other passage. Follow the passage and crawl through the gap. Stand up on the other side. Climb out to the right and follow the path towards two switches on the right wall.
Right DoorUse the right switch. This operates some timed doors. Make a roll and sprint into the passage on the right. Make sure you get around the corner without getting stuck. Release sprint. Sprint along the next part. At the end, make another roll to turn around quickly and sprint through the door in the right corner. Be careful not to drop into the pool. Use the switch to operate a trapdoor in the room left to you. Slide down and follow the passage out to the right. Collect the flares in the middle of the long passage. Return to the switches.
Middle DoorUse the right button again. And sprint along the passage to reach the middle door in time. Light a flare in the chamber behind it. Climb up the step. On the right, you can see an opened trapdoor. This is the one, which was operated by the switch behind the right door. Climb up on the left. The door closes behind you. Use the next switch on the right to open a grating, which is the connection between this passage and the left chamber. You will need this closed in the left chamber, otherwise you cannot monkey climb into the alcove. Follow the passage to the end and drop down. You are back at the two switches.
Left Door - 2nd Solomon's KeyNow use the left switch to open the left door. Sprint along the passages like before to enter the chamber on the left. Inside you will find a pool. Climb onto the block on the left. Jump up to the grate at the ceiling and monkey climb along to the other side. At the end let go at and grab the lower ledge. Pull up. Collect the crystal, the shotgun ammo and Solomon's Key. Jump into the water. (Don't climb out into the passage this is only of use if you have to return to the buttons because you've forgotten to lower the grate.) Dive into the tunnel. Climb out of the water at the end. The door at the end opens and you will emerge back at the ticket booths. Kill the Damned. Use the coin at the front side of the third ticket booth. Pick up the ticket you got.
The MazeRun down the left escalators. Run onto the pile of soil and shoot the Damned coming from the left.
Turn right at the end. There you will find another switch 3. Operate it to open the door in the left corner of the chamber with the Number 2 switches. (It will also close some of the other doors, but don't worry.) Run back into the previous chamber and turn left to get into the opened niche. Collect the small medipack. Then return to the switch 3 and use it again.