Dexter: Resurrection's central twist is that Dexter Morgan survived being shot by Harrison in Dexter: New Blood. The freezing temperatures of Iron Lake preserved him long enough for medical intervention. Upon awakening, he tracks Harrison to New York City. The season's main antagonist is not a single serial killer, but a collective: a secret club of murderers patronized by billionaire Leon Prater, played by Peter Dinklage.
A major turning point is the murder of Angel Batista in Episode 9. Prater, wanting to prove himself as a true killer, shoots an unarmed Batista multiple times, trapping Dexter in a vault with the body of his former friend. This act removes one of the few remaining original characters and provides Dexter with a deeply personal motive for his final kill. In the finale, Dexter's son Harrison does not partake in the final kill. Instead, he helps Dexter escape and subdues Prater with a sedative Dexter had given him earlier for protection. Dexter then kills Prater alone, avenging Batista. He recovers his original blood slide box, symbolizing his full return to his old ways. The ending sees Dexter and Harrison united, with Dexter sailing off on a yacht, dumping Prater's body, and fully accepting his identity as a killer with a purpose, now anchored by his son.