Dexter: Season 1

Dexter and the department hunt a fellow serial killer nicknamed the Ice Truck Killer, whom Dexter discovers to his horror knows his secret identity, and whose grisly work triggers Dexter's suppressed memories of his childhood; Dexter's sister Debra transfers into the Homicide Department; his girlfriend Rita deals with the surprise return of her paroled ex-husband, who doesn't want Dexter around his kids.