In the Season Four premiere, Dexter sleeplessly struggles to balance his new family life with his dark, murderous drive for a fresh victim, and his busier-than-ever forensic career pursuing a new target, "The Trinity Killer."

Dexter realizes that he has carelessly misplaced crucial evidence that could expose his dark side to the world, while helping to investigate new slayings that Agent Lundy insists are the work of Trinity.

Dexter is hampered by his neighborhood's increased vigilance due to vandalism, his temporary inability to drive himself anywhere, and his admiration for the killing technique of the artful Trinity Killer.

Dexter gets some much-needed R&R time with Rita and the kids out of town, leading to his stalking of a new victim - until he unexpectedly begins to empathize with his target, a cop that murdered her family.

Dexter is inspired to investigate the Trinity Killer on his own, while Debra blames herself for an event that was out of her control, and Rita realizes how little she knows her husband after discovering one of his secrets.

Dexter doubles his efforts to stay ahead of the official Trinity investigation, and receives relationship advice about the friction between himself and Rita from a most unexpected source.

Dexter finally strikes a balance between family, career and his secret life, but is thwarted in his pursuit of his next victim, while Debra expresses a renewed and unwelcome interest in their father's checkered past.

Dexter wonders if his father's Code is truly the right path, and hopes to get answers by accompanying Trinity on an out-of-town road trip, while Debra discovers that her single-minded pursuit of Trinity has blinded her to the truth.

Dexter learns more about Arthur's bizarre and twisted world, while Rita has her hands full preparing Thanksgiving dinner for a full house, Debra uses the holiday to further investigate Trinity, and Batista gets closure on an old c...

The disappearance of a ten-year-old boy forces Dexter to question his assumptions about Trinity, while Cody defends one of Dexter's lies and Masuka is unable to face what he witnessed on Thanksgiving.

Dexter must buy time to protect himself when Debra's investigation brings the department one step away from identifying Arthur as the Trinity Killer; Rita confides in Dexter, but is disappointed in the result.

Dexter and Arthur find themselves on a collision course, as Debra unearths a shocking long-hidden truth, Rita admits her marriage to Dexter is troubled, and Batista and LaGuerta face the consequences of an ethics breach. Season Fi...