The Ice Truck Killer leaves a clue at the scene where Dexter has dispatched his latest victim, and Dexter is worried that someone might have witnessed his killing. Rita is trying to deal with her ex-husband.

The squad identifies the Ice Truck Killer; Rita's ex-husband, an abusive addict, is paroled.

Dexter appears to be connected to a psychiatrist suspected of murdering a suicidal patient.

While on a weekend getaway with Rita, his sister and her new beau, Dexter learns that his biological father, thought to be dead for 30 years, has just passed away, and that he's willed his son everything he owned.

The Ice Truck Killer prepares a crime scene for Dexter: a hotel room all covered in his previous victim's blood. But Dexter does not appreciate this gift, because his childhood memories hunt him.

The Ice Truck Killer sets a trap for Dexter by kidnapping someone close to him; Dexter's increasingly odd behavior piques Doakes's interest.

Dexter figures out who the Ice Truck Killer is, along with a dark secret from his troubled past. Meanwhile, La Guerta is replaced with a new boss and Angel figures out a way how to track the killer while he's still in hospital.

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.