Hall of Demetrius is the eighteenth level of Tomb Raider: The Last Revelation. In it, Lara continues her quest for the Armour of Horus...
Continue through the hallway to reach a huge room with balconies all around. Go through the opening on your right (south) and run up the ramp. Get the Pharos Knot from the pedestal and return back down. Go through the opening on the other side (north) and run up the ramp.
The cut scene shows Lara kneeling, as she gets ready to read a Scroll from the floor. She suddenly hears something however and glances around. She starts reading anyway, but Von Croy and three of his men interrupt her. It seems Lara fell into his trap, and Von Croy tells her she has found the Scroll they unearthed. The Scroll says that the Armor needs the Amulet so it can be an important historical artifact. There is more, though, stuff about rebinding the spirit of Set, and putting the armor on the statue at midnight at the turn of the millennium. But Werner Von Croy has never believed in 'hocus pocus'. Then Lara jumps off the balcony and Von Croy orders his men to get her. Meanwhile, Von Croy sneaks off through a secret door.
After the cut scene you find yourself back at the bottom of the Hall. The three ninjas come from the nearby doorway (north). Take care of them one by one or by exploding them all and go up the ramp. Push\ pull the movable lamp towards the doors where Von Croy left. One of them opens, so it is obvious where to go now.
Back to the Coastal Ruins - When you drop through the opening, you change level and end up back at the Coastal Ruins. If you have been avidly following this walkthrough so far, you have all the necessary components in order to continue with the game.
Facing the pool, jump up to grab the ladder on the west side of the opening above the platform. Climb to the top and follow the hallway to reach the outside area. Jump into the water and swim to the northeast side. Swim through the opening on your right and follow the underwater tunnel. In the small room with the pyramid, go to the left. The current will take you to the next level Pharos, Temple of Isis.