I've been meaning to try and pinpoint the first episode we are made aware of this. Anyone know off the top of their head?

EDIT: I just read that it's "Proshai, Livushka," where his cooperation is first revealed. I still don't remember the scene specifically though. So he was one episode away from being a rat for a full 3 seasons, and nothing ever really came of that storyline.

I dream in widescreen.