Turn right and jump to the ledges. Climb to the top. Face to the column, jump to grab the salient ledge and jump twice times to the next edges as you stand on the cast iron bridge on the high level of the chamber.
Go to the niche with movable gear, move the bar - the chamber will fill of the water. Jump into the water and swim in the direction of the platform. Dive and take 50 caliber pistols ammo from the niche on the right side. Under the water you will also find the lead for the rifle.
Swim to the raft and climb on it. Jump to the small bridge under the wall, where is a niche with carved heads. Throw to grab the line on the band of the raft and push the raft on the place, from where you can jump into this niche.
Jump to the raft and then to the niche with carved heads. Jump to the small pond and dive. You will come to the underground chamber.
Go out the pond, take shotgun ammo and back to the water. Find the underwater tunnel and swim through it. You will come to the enormous underground chamber with the tomb of Tihocan. Dive in place exactly opposite to the entree. Swim through the corridor. There is a cave with the lever - switch the lever and the gate to the tomb will open.
Surface and go to the waterside. Go through the open gate into the tomb. Take Scion of Tihocan.. Suddenly Dupont will appear and take the artefact from you.
The fight with Pierre will start - your task is to pushing the right direction keys. In the end Dupont will escape.
Outside the building two statues of Centaurs will awake and kill Dupont. Be careful, now they want you. You should evade their hoofs and flaming green orb, which can turn you into the stone. You must kill centaurs one by one - fight with one and evade the second. Using the orbs to drive mad Centaur and when he attacks you, dodge and shoot at him. When he stands for the moment, throw the line on his protecting shield and take it. Do the same with the second centaur.
Again drive him mad - now he wants to change you into the stone. Use the shield to protect yourself. The beam will miss him. Now he is weak and easier to kill. In this way you will defeat them. More information about the fight is in the chapter IV. THE BOSSES.