Sam learns that a dangerous gang is targeting his old friend Juan, who is doing time in prison. With the FBI’s help, Michael breaks into prison to keep Juan safe. When the gang starts a prison riot in order to take out Michael and Juan, Michael realizes getting out of prison alive might be more difficult than he initially thought.
Meanwhile, Michael comes face to face with an old nemesis, Simon (from Season 3 Episode 16) in order to get a step closer to finding the identity of the man behind the rash of worldwide terror. Simon agrees to help Michael, pointing him to a historic graveyard were Simon has hid some of his deepest secrets, but Simon warns Michael that digging up his booby-trapped treasure trove might not be such an easy task.