Now that you've made friends with the immortals you can continue without worrying about them. Be sure not to shoot any of them on your way, or they will turn against you. Follow the immortal down the hallway to the next chamber with the two small pools. From here go through the hallway on the left. When you slide to the room below, be quick to jump to the ledge on the right - before the spiked ceiling has its way with you.
In the next room there is a switch, don't push it just yet. Go through the door into the open area. Go to the right and hang from the ledge and drop down behind the spikes below. Shimmy your way over to the right as your feet dangle just inches from the barbwire. On the other side, climb into the room to find your secret. Light a flare to help you find your way, jump up to the ledge and continue in that fashion. You have returned to the open area; now go and push the switch and climb the ledge to your left.
Climb up the mesh to the red light above the barbwire. From there you can back flip and spin in midair to grab the ladder and retrieve a rocket. Climb up just above the green light and back flip and spin in midair. Don't try to grab the ledge, Lara will land on it by herself. Retrieve the save crystal and jump back to the mesh and make your way up to the crawl space at the top. Crawl through to the end and get your shotgun shells; then backtrack to the area where you could stand, jump up and drop into the room, but watch out for the bad guys. Move the box to gain access to the Egyptian room. Push the button to open the door.
Enter the Egyptian room and climb the pillars. Jump up to the ledge above the pillar and you will notice the switch on the ledge across from you; jump across and pull the switch to close the door to climb the ladder. Return to the pillar and monkey swing to the two ledges on either side; one holds a save crystal and the other a switch that opens a door high above on a ledge. Climb to the balcony above using the ladder and jump to the ledge on the left. Pick up the items and be sure to save your progress at the slope. Slide down the slope, being sure to jump across to grab the ledge or you'll be in for a nasty fall. Follow the walkway to the next sliding ledge, this time slide down to the collapsing ledge below. Do a standing jump to the ledge and retrieve the embalming fluid and continue through the crawl space.
Be quick when entering the next chamber or the guard will shoot you. Dispose of him and go through the crawl space to the next chamber. After checking your health, kill the guard and open the door to pick up the rocket before going the sphinx room. Monkey swing across the room high above the sphinx, taking note of where the wide view is given. At the other side retrieve your save crystal and monkey swing back to where the wide view happened and drop down to the sphinx's head.
Turn around and face the back of the sphinx and walk to the left corner and line yourself up with the slanted part of the ceiling. Jump back once and do a standing jump; you'll land on a ledge with a small medi pack. From there do a standing jump from the edge to the pillar nearby. From the pillar, run and jump to the edge of the slope and slide down to jump the walkway. Run to the end of the walkway and pick up the rockets and the save point. Make your way down below by using the sphinx to break your fall, and run around to the other side of the sphinx and dispose of the guards and go up the stairs. At the end of the hallway jump to the ledge above and pull the box, allowing you to climb to an upper hallway. Drop down at the other end of the hallway and pull the box out; then go back through the upper hallway and drop down with the box behind you.
You are now back in the chamber with the two small pools. Go up the hallway on your right and place the embalming fluid on the ceremonial niche, and a doorway will open. Fall down the trap door into the water and swim down to get your underwater propeller vehicle (UPV). From there the current will suck you into another area.
Follow the left wall and through the passage, which the current pulls you through. Leave the UPV and swim through to the other side to the glass window. Pull the lever that opens a trapdoor just in the passage you're in and light a flare to help you find it. Climb out of the water and up to the ledge, and push the button that will open the door to the tunnel, which brings you to the next area. Swim through but keep low, climb out of the water and kill the guard. Search the area for items. Go to the back room and swim down into the tunnel to dispose of the frogman and the crocodile.
Once in the large chamber, swim to the right and to the far upper-left corner. Here you will find an air chamber. Beside the air chamber you will find a UPV. From the air room go to the bottom left chamber and pull the lever to return to the air chamber. From there go to the chamber with the green lighting above the tunnel - with the open door - and pull the lever. Return to the air chamber.
Across from the air chamber, go to the chamber with the red lighting to get your save crystal, and pull a lever. Now some frogman will be on the prowl. Dispose of them and return to the air chamber. Go to the chamber to the right of the air chamber and down through the trap door. Surface and drop to the murky area below the flaming ledges and pull the switch to shut them off. Jump across the ledges and dodge the piston. Monkey swing to the waterfalls and go down the passage to open the boiler room. Swim to the crawl space then jump across the ledges to the purple one. Now it's time for the showdown.