Fyodor and you are now in the control room with camera films in this prison. You just watched Fyodor having a mental breakdown, that might've been just part of his play, or not. He offered you a knife to kill him, but just as you're ready to take it, Fyodor takes a hold of the knife himself and stabs you into your stomach. As he's doing so, he whispers into your ear.

"Sake."

He's a traitor it seems.