Dexter sets his sights on a new victim: a murderer so repulsive it seems only fitting that he’s a used-car salesman. Dexter’s been unable to lie to Rita about his midnight activities, which has her thinking that he’s a drug addict. She’s threatened to leave him if he doesn’t commit to a 12-step program to deal with his supposed addiction. While in this recovery, though, Dexter meets a sexy, mysterious woman named Lila.
Brother Sam, a minister with a criminal history, is brought in by the homicide department to help solve a macabre murder, but Dexter sees him for what he really is, and it’s definitely not a man of God. Elsewhere, Debra’s sudden hero status elicits a pair of surprising proposals.
Dexter is finding it hard to have closure on killing his brother. There is a new FBI agent to head the “Bay Harbor Butcher” case. Debra is finding it tough to put the past behind her.
Things are really beginning to heat up for Dexter: Doakes’ suspicions about him are growing, his victims are escaping, and his body dump site has been found. Meanwhile Paul is troubling Rita over the missing shoe and Debra is going through trauma over the Ice Truck killer incident.
Dexter shows up at his 20th high-school reunion with the intention of confronting the former prom king. Elsewhere, an investigation into a heinous murder with religious overtones leads Dexter to ponder spiritual matters and wonder about his son’s legacy. And an unexpected situation results in Debra becoming a hero.
Dexter follows clues left for him by the Ice-Truck Killer in an attempt to find the hostage. Paul tries to convince Rita that she and the children are not safe around Dexter.
The Ice Truck Killer puts Dexter in a life changing position when he takes someone close to Dexter hostage. Doakes begins to suspect that Dexter’s odd behavior is something darker than he originally thought.
Dexter’s situation grows desperate when he discovers that Lumen’s been set up. Despite knowing he’s being baited into a trap, Dexter risks everything to make sure he doesn’t fall into the same mistake again. In the Barrel Girls case, Debra lets her personal feelings lead her instincts once she concludes that vigilantes are more than just a theory. Quinn finds himself in a troublesome situation, which only Dexter can help him out of.
The Ice Truck Killer is back. He leaves a crime scene that brings back some horrifying repressed memories for Dexter. Paul sues Rita for sole custody of Astor and Cody.
Dexter receives notification that his biological father has recently passed away. Dexter is named as the sole heir of all his possessions including his house. Dexter goes for a weekend away with Rita, Deb, and Rudy.
