Uncharted 3 Walkthrough Chapter 21 - The Atlantis of the Sands

In the previous chapter, after rescuing Sully from Marlowe's convoy at the desert canyon, you arrived at the lost city of Iram.

Head down the stairs and between the statues. Welcome to Ubar.

Go down the spiral staircase. Enter a room with a working fountain. Incredible. This how the city could thrive all the way out here. The whole place must be fed by an underground spring. Taste the water. It's clean. It's amazing this thing is still running after all these years. Look around. A solar eclipse is happening.

Suddenly you hear a loud bang. Sully has been shot by Talbot and is dead. Kate Marlowe and Talbot are entering some kind of round elevator. You start going after them. Some of Marlowe's men appear. But wait, these are not ordinary men. Their heads are aflame! These are  fire spirits. Shooting them in the head is no use. They are more resistant to damage, and can teleport from one spot to another. Use sniper weapons and explosive weapons against them.

Once you have defeated them, enter the elevator. It will start going down. Talbot will be waiting for you downstairs. As soon as the door to the elevator opens he will throw some kind of smoke bomb in it. Give chase through the streets.

You will arrive at a dead end. Suddenly the streets look familiar. It looks like Cartagena, where you grew up as a kid. Suddenly swarms of spiders are chasing you. run away through the door. You will suddenly see yourself as the kid. Keep running through the cartagena hotel roof, and to the balcony. You will arrive at  another roof. Sully approaches, aiming a gun at you. He shoots you! But you wake up. Looks like you were just dreaming.

Keep running through the streets. Everything looks fuzzy. You arrive at some gate and it looks like there is no way out. An elevator comes down and more fire spirits show up. Kill them. The gate will open, go through it. There will be more demons on the other side. Climb up the stairs and reach a fountain. There will be another battle with the fire demons.

Keep going through the streets. You will see Sully in a courtyard but it looks like an illusion. There is some device, push the lever to fill the pool with water. This is actually some sort of puzzle. Watch carefully the reflection of Nate in the pool. He will go towards a wheel on the side of the pool. Go there and turn the wheel using the green triangle button. Then the reflection will go to the other side. Follow it, and turn that other wheel. Enter the pool and tap green triangle button to try and pick up the shiny object in the center. A reflection of Nate appears and throws you in the air through some portal.

You wake up in the middle of a drained out pool. The entrance ahead is now open, so go through to reach another fountain. Head down the spiral staircase, towards the last chapter of the game.