After the flashback in the last 2 chapters which took you to Cartagena Colombia and showed how you and Sully became friends, you are now back to London, England, at the alley behind the pub, after having been shot by Cutter.

Turns out Cutter is Sully's friend, and this meeting was an elaborate setup by Sully and Drake in order to get to Marlowe. Cutter was in on the whole thing and helped organize this act, which made it appear as if he had shot Nate and Sully, but it was all for show. Furthermore, Nate did not give them the real ring.

All that racket could bring the cops any minute, so you better get out of there. Start moving, your goal is to follow Marlowe's crew to their base. Go through a little alleyway. Climb over the fence. Cutter suggests you get around the door. Climb over the pipes. But cutter use some muscle to knock the door open. Push the yellow cart onto the wall. Climb on it and jump over the gate. Go past the red phone booth. You will run into Chloe (Return from Uncharted 2) in a white van. She had trailed Marlowe's car, and she doesnt think they saw her following them. She will tell you Marlowe went through the green door. She will hand guns with silencers to you. Your plan is to sneak in and sneak out.

You have to find a way in. Climb onto the pole to the right of the green garage door. Climb it to the end. The pipe will break, jump to the next one. Shimmy up the wall and hang on the roof. Land on the holed roof below and keep going. See the window with the satellite dish, climb on the rail there. Jump to the lamp post, then to the sign. Noone is in there which seems strange. Get to the open window and go in. keep hanging to the pipes, then take the window out, and keep going. Drop down. You will be behind the green door. Hit green triangle to open the garage door. It is very strange that there is no sign of Marlowe's crew, nor the car. How could the car have vanished? You can still smell the exhaust so the car was there all right. Spread out and look around.

Observe the tire tracks on the ground. Looks like the car turned there. Note the four panels on the ground with wet tire marks on them. Stand on one of them, to discover that they are actually pressure plates. Go stand on another one of those plates. A cutscene will start. Its some kind of mechanism. There are four tires, and four points of contact. Have everyone stand on a different pressure plate. Press X when Nate counts to Three to jump. Press up arrow to enter look mode and use right stick to scan the environment. Aim the light at the wall, simulating the headlights of a car. Suddenly two panels will open, and the door will slide open as well. There is a tunnel behind.

Enter the tunnel, and move through it. You will reach a closed gate and locked door at the end of the service tunnels. Shoot the lock on the door. Press Green Triangle button to open the door. Climb down the stairs and through a narrower tunnel. Squeeze through the pipework.

Head towards the exit to the tunnel. You will knock down a wooden plank, and it will cause noise and attract the attention of the two guards patrolling outside. They will start shooting at you.

Shoot back. Press L1 to aim, and R1 to shoot.

After you've killed them, enter the room with the two big generators. Two more guards will show up, neutralize them as well. Climb up the ladder. Cross the bridge. The tunnel is right below you. After youve crossed the bridge jump down to the sewer. Go through the circular doorway to arrive at a very deep pit.

Slide down the vertical pipes and work your way down to the bottom of the shaft. After you land, wait for Sully and Cutter before going through the door. Therell be more henchmen coming, hide and shoot them when they come close. You will come onto a passage and a ladder, looks like it jammed though. See if you can loosen it.

Climb the pipes up to the ladder and lower it a bit. Climb up. Looks like there's some sort of  gate up there. Give Sully a boost (Green Triangle Button) so that he makes it to the right side. He will reach the ladder and climb. In the meantime you go and climb on the yellow dumpster, and up the pipes. Reach the levers, and pull them at the same time with Sully by tapping the triangle button. This will lower a drawbridge. Climb on the bridge and to through the door. Go down yet another tunnel into a narrow cavern.