Season 1: Completely different - Dexter hunts a ritualistic cult-style killer by the name of The Phantom (similar to Travis Marshall). Ends with Dexter unsatisfied by the kill, questioning his purpose.
Season 2: Bay Harbor Butcher arc like in the show. Around episode 7, Dr. Danco is introduced, targeting victims with surgical mutilations. He kills Doakes in the finale before Dexter stops him.
Season 3: Miguel Prado arc remains, but Freebo is replaced with the Skinner. Miguel manipulates Dexter into helping, Dexter and Miguel kill the skinner together, but Dexter kills Miguel when he becomes reckless.
Season 4: Same as original. Trinity Killer murders Rita, shattering Dexter.
Season 5: Lumen removed. Dr. Vogel introduced, revealing her role in creating the Code. Dexter learns from her tapes that he has a brother.
Season 6: Brian finally appears, echoing the Ice Truck Killer arc. He tempts Dexter to abandon the Code. Dexter spares him instead of killing him.
Season 7: Dexter and Brian reluctantly team up to stop a new cannibalistic threat (Roberto Acosta and The Coven). Deb grows close to Kyle Chutsky and becomes pregnant. Brian disappears by the finale.
Season 8: Deb gives birth to Nicholas Morgan. No Dark Passenger tie, Nicholas is normal. Dexter struggles to raise Harrison while continuing to kill. New villain: Elliot Budge (a stalker who discovers Dexter is a serial killer). In the end, Dexter fakes his death so Harrison can grow up safe with Deb, Chutsky, and Nicholas.
