London Underground

You start off after the crocodile ride, heading back out of the library. Keep moving through the tunnel, and be ready for some of Marlowe's men. As you exit into the old train station, more enemies will show up. Your best bet is to stick to the left side of the area and push forward. This way, you can keep them in front of you and avoid getting flanked. Once you've cleared out the immediate threats, look up above the trains. You should spot the Silver Hunter Pocketwatch treasure perched on an outcropping.

Continue towards the iron elevator. You'll encounter more enemies, but with all the cover available, they shouldn't be too much trouble. You can't go back under the elevator, so take the new path on the left and head up the stairs. You'll find some propane tanks behind the first guy you see who's carrying a shotgun. Use them to take him out, then deal with the other two enemies. After that, climb up the ladder.

Emerging into another circular tunnel, immediately take cover to your right. There are enemies with laser sights further ahead, so you'll want to avoid their aim. Move up cautiously when it's safe until you reach North Atwood station. Stay low on the ground here and clear out any enemies trying to sneak up behind you by moving along the tracks. Also, keep an eye on the platform above so enemies don't get the drop on you. Once the area is clear, check the front of the red train car for the Art Nouveau Flask treasure.

From the platform, head towards the stairs to go up toward the surface. As you approach the next group of enemies, you'll notice laser sights coming from the other side of a gate. Your best bet is to roll forward to dodge their aim and get a clearer shot, or if you're feeling brave, just sprint for the tunnel once the standard enemies are dealt with.

As you run up the tunnel, keep an eye on your back because more enemies will be coming from behind. You'll need to shoot the lock on the gate to allow Sully and Cutter to pull it open so you can make your escape.