FX: The Series - Season 2 Episode 10 Flashback

With Rollie's help, the assassination of a US Senator is recreated in a movie, and then in real life -- with the original assassin! When it's discovered that Orrin Hill, the assassin, has a brain tumor erasing his memory, a plot is hatched to convince him he's back on that fatal day in 1979. Lost in a time warp, he must do the deed all over again, allowing Rollie and Mira to track him to the source of the conspiracy -- the man who got away, eighteen years ago.