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 hopes to clear his son Kyle of murder charges by looking for Jordan Collier, who might still be alive. Meanwhile, Diana receives a surprise visit from her sister April and her new fiancé.