From your starting point, run down the hallway to find a button. Push it and enter into the crawlspace at your feet. Go right, but watch for the laser overhead. Run to the end and grab the upper ledge. Go through the crawlspace and wait for the guard to pass. Quickly crawl out and dispose of the guard before he makes it to the alarm. Go through the crawlspace on the right and down the hallway to avoid the laser. At the end of the hallway, pull the switch and fall through the trapdoor under your feet. Once outside, run around the pillar and shoot the guards. Check the area; you'll see a submerged gate. Fall down onto the catwalk, pull the switch, and jump through the trapdoor. Get ready to blast away at the guard below. Crawl in the nearby passage and shoot the MP. Go around the corner and release the prisoner. When you return to the hallway, you will notice that the prisoner has taken care of the guard. Continue down the tunnel, but be careful not to trip the alarms on the way. Go left and pull the switch, then go right into the passage. At the other end, you'll find a junction. First, go to the right hall to the rocket room. Climb the ladder, dispose of the sniper, and pick up the code clearance card. Make your way back to the junction, but this time, go the other way. Enter the other room, but before jumping down, shoot the guns in the corner of the ceiling. Now, insert the clearance card that will raise the rocket. Be careful of the moving pulley. Shoot the red grill to enter the passageway and climb down the ladder to find a secret. From where the rockets lifted, jump to the ladder, climb up to the rafters, dispose of the sniper, and retrieve the key. Return to the rocket room, climb down the ladder, and enter the blue hallway. Use the key. Shoot the sniper and head up the tracks. Climb the ladder and push the switch. The train is now on the tracks. Don't touch the electrical tracks, or you'll get quite a jolt. Crawl under the track, climb the ladder, jump on the train, and climb up to the floor above you. Run across the first catwalk. Then, grab the ceiling and monkey swing across, being careful to avoid the moving laser. Drop down where the floor is green. Cross the tracks and run after the guard. Shoot the enemies along the way up and avoid tripping the laser. Climb up onto the boxes and take out the guards before they get to the alarm. In the next room, shoot the sniper and climb up to the first balcony. You'll see a switch on each balcony that opens the door to the next room. The switches are timed, so you must be fast. Push the switches just once and get rid of the snipers. Once the snipers have been eliminated, push the switches again and use the control panel to move quickly from one balcony to the next. Sprint for the doorway. You'll enter a room with six switches. Shoot the sniper, then push the two last switches and the second one from the left. That will open the UFO room. Return to the UFO room and push the switch. Climb the ladder and back flip onto the rafters. Jump onto the balcony above the UFO and pick up the launch code pass on top of the UFO. Backtrack to the rocket room. Insert the launch codes to access the switch and then make a break for the next room before the flames from the rocket burn you. Return to the room where the rocket was launched. Climb the ladder and shoot the sniper on top, pull the switch, and enter the doorway. Crawl and then jump over the moving laser to get to the other side. Climb to the ledge above the right corner. Shoot the guard and sniper on the roof. Enter the room and pick up the code clearance disk. Pull the switch and fall down into the trapdoor. Go back to the UFO room and enter the code clearance disk. Now, return to the rafters, jump into the doorway, and follow the hall to the pool with the whales. Return and enter the UFO, being sure to dispose of the guards. You now must climb higher and enter the dark corner. Shoot the sniper and pick up the relic to end the level.