Tom and Diana are drugged with a hallucinogen, created by a 4400, that causes them to confront significant people from their pasts.

Kevin runs for his life when he becomes a marked man because of his promicin research; and as Tom and Diana search for him, they discover the depths of his devotion to his work. Also, Shawn meets his idol at the 4400 Center.

Tom and Diana probe a series of gruesome murders. Meanwhile, Shawn receives a gift from a 4400 that lets him see his future.