First, turn off all four pipes leaking green gas in the corners of the room. After that, shoot the rope tied on the wall, near the far end of the room, to drop the box hanging from the ceiling onto the vent that the green light is coming from. Then, shoot the other rope tied to the wall near the railed door to drop the covering to the vent. The final vent covering is in front of boxes which will explode when you shoot them. After these vents are blocked, drag the box over the vent nearest the dead inmate. Next, wait for him to get in front of the fireplace and take the from of a man. When he does this, turn the crack so that the gas pushes him into the fireplace. Finally, run over and shut the door.