S6, E16: The FBI suspects foul play is involved in the disappearance of a lottery winner who has vanished after coming into millions. Sprague Grayen (Jericho) guest stars as Paula Reiser, the missing winner's best friend. Meanwhile, Jack runs a background check on Brian Donovan (recurring guest star Adam Kaufman), the father of Samantha's unborn baby, and discovers some troubling information about him.