Dexter (2006): The Getaway

The Season 4 finale brings Dexter's hunt for the Trinity Killer, Arthur Mitchell (John Lithgow), to a head. While Debra uncovers a long-buried family truth about Dexter's birth mother, and the police work out who Trinity really is, Dexter persuades Rita to leave town and finally catches Arthur. Spoiler: he kills Arthur with a hammer, then returns home to find Rita dead in the bathtub, with baby Harrison crying beside her. Directed by Steve Shill, who won the Emmy for Outstanding Directing for a Drama Series for this episode, it drew 2.6 million households, Showtime's biggest audience for an original series episode at the time.