SPOILERS, SPOILERS, SPOILERS ! About the ending of Requiem...

[Penumbra]

Spoiler below!

In the end, you blow up this wall of rubble blocking your path. Then when you walk in, your at the opening to the shelter again where Red was, its just like in Overture. Then you go to the furnice and Red is waiting inside of it, just like before.

Philip presses the button and either just Red gets burned again, or him and Philip get burned. You hear alot of screeming and then it fades away to a view of Philip laying on the floor in front of the computer that he sent the message on.(dead or alive)