Episode 4.15: titolo Unknown
Airdate: December 15, 2008

11/11 - The series welcomes back a familiar face from season 1 in the Dec. 15 episode: Muse Watson, a.k.a. Charles Westmoreland. No, he's not quite back from the dead; Michael interacts with his old prison pal while in a dream-like state during brain surgery. Source: Entertainment Weekly
11/11 - According to Matt [Olmstead], something big is coming down the luccio in episode 15. Says Matt, "It's something that we had talked about that was similar to bringing Sarah back, essentially. Which was when - it was a discussion we had back in season...