Season 1

Young Dexter Morgan is a pre-med student in 1991 Miami, living with urges he’s never acted on. At a fair and later at a party with his sister Debra, an event ignites something in him. When an older nurse caring for his father turns out to be poisoning him, Dexter makes a dark decision. He graduates and starts working for Miami Metro, feeling the pull toward something he cannot ignore.

Dexter begins his internship under Masuka and starts to see how the forensic world views crime. Outside that, family tensions with Harry and Debra drive him to experiment with morality. When a masked kidnapper’s finger is sent to the police, Dexter’s curiosity grows about what’s wrong and what’s right.

Dexter targets a loan shark with connections to Batista, trying to prove himself in his role. Deb throws a party hoping to impress for her volleyball team. Dexter also becomes aware of trophies tied to his darker side when earrings belonging to someone close reappear.

When a retired mob hitman possibly continues killing, Dexter investigates. Meanwhile, Harry works a grim case involving a murdered ten-year-old boy. Deb sneaks into a nightclub with Sofia, where she meets someone new.

Dexter is reeling from a misstep in his plan with the hitman. Harry warns him off future recklessness. Deb attempts to reconnect with Dexter after her own emotional struggles. Dexter looks into a sedative that might allow him more control over how he handles his victims.

Dexter’s violent urges become harder to ignore. He targets a new victim, Levi Reed, in a more methodical way. Meanwhile, other investigations — including the kidnap case of Spencer’s son — escalate, putting pressure on Dexter and those around him.

Dexter must find a new place to dispose of his victims after his usual spot is compromised. The search for a missing child intensifies. Deb has challenges with teammates at volleyball. Harry and LaGuerta push a controversial theory to Spencer about connections in the disappearances.

Dexter’s double life grows riskier as he handles both daytime forensic duties and night-time urges. Relationships around him become strained. He must balance protecting his family, covering his tracks, and satisfying an inner need he’s been trying to outrun.

Tensions reach a boiling point. Dexter faces growing scrutiny at work. The crime scenes pile up. Dexter is forced into choices that test how far he’ll go to preserve what he wants and who he’s becoming.

In the season finale, Dexter’s world shifts. He pursues Spencer to locate where a child is being held, while his biological brother Brian takes steps to get closer. Dexter’s adoptive family moments are shadowed by betrayal and emerging truths. The stakes are made clear: there’s no going back now.