After a short corridor you get into a room with the White Hourglass. You'll be attacked by spectres and ghosts. Ghosts are easily to be defeated - your main enemies here are spectres
Besides summoning ghosts, they can hide in the floor. From there they can attack you, but you can't retaliate. Take them out using Grab button.
You can knock them up, nonetheless the battle isn't simple. Use all you've got. Stunned ghosts are perfect weapon - remember to throw them nearby the remaining enemies.
There are few useful items in the chamber. A big trapdoor under the Hourglass which lowers the elevator; small, round trapdoor before the elevator. Hanging chandelier. Broken gas fountain. Two locked rooms at the end of this chamber, on left and on right.
Firstly, stand on a small trapdoor. It open two rooms. When you move out, the right one remains open. Go there, open chest and use lever. It launches the gas fountain.
Go through the green cloud and return to the room with the beam. Destroy door inside. Behind it, you find red chest and white one with Gorgon Eye.
Again use the gas and run to the left side of the room. Destroy a column marked with the white light. Step on ruins and jump onto a wall on left. Climb up and go right.
Jump onto a chandelier and swing it by grabbing the statues' heads. Now jump onto an Hourglass and further on to the higher level of this room.
You'll be in front of the altar and wall painting. On right you find Aletheia's Charm.
Move right, you find closed door and red chest. Open it and return to altar and then keep going left. Use a lever and enter the room where you've been fighting Talos.
Pass the fountain and enter the elevator to pick up chests. Use the gas. A wooden bridge will fall down next to the fountain. Jump down and defeat enemies.
Here you meet Harpies for the first time. Avoid their feathers (their wings begin to glow). Fight with them like with other flying monsters - grab and knock them up.
After the fight grab a part of the statue and drag it to the complete one, in the place where wooden bridge falls when the time changes.
Use ladder and sniff gas. Jump down quickly and push the statue on a fallen bridge. When the time returns to normal, everything will be on a higher level.
At the beginning of the chapter, just in front of the Soul of Hades are door which you can destroy after the time changes. Do it now. Use the fountain, jump down and run left. Pass the chamber with Soul of Hades and destroy door before returning to a normal time. Behind the door you find two white chests with Gorgon Eye and Phoenix Feather.
After that return to the recently used fountain. Use the gas again and run right. Destroy door blocking your way to the chamber with an Hourglass. Then, drag a statue taken from the ground floor through it.
Place the statue on a smaller trapdoor.
It opens the room on the left side of chamber. Go there to collect a Note from Castor the Prophet, two red chests and one white with Phoenix Feather.
Return to the main hall and push the statue to the Hourglass, so you can jump onto a chandelier when it falls. Use green gas, jump onto chandelier and swing it. It destroys the Hourglass and you leave the room.