Dexter is a forensic expert in blood patterns who works with the Miami Police Department. He is also a serial killer, who kills people that the police can't bring to justice. He has to hide his double life from his sister, his girlfriend and his co-workers. He is intrigued by a killer who has found a way to kill girls without leaving blood behind.
Being wrapped up in preparing for his next victim, Dexter, finds out that the Ice Truck Killer is aware of Dexter's dirty little secret.
Dexter's on the trail of a recently released murderer who plans to kill again when he's sidetracked by the Ice Truck Killer's latest crime - a cut-up hooker found in a hockey ice rink.
The Ice Truck Killer begins leaving pictures from Dexter's childhood at the crime scenes. Is the killer trying to tell Dexter something about his own past?
While the rest of the police department are focused on finding the Ice Truck Killer, Dexter is busy gathering evidence for his next victim. It turns out he will also discover more about relationships, love and how to make a success of it all. In doing so he gets some hilarious advice from unlikely sources and we see the first time that he actually kills two people at one time.
Dexter is called to the scene of the crime at the Castillo junkyard. The Ice Truck Killer has returned Valerie Castillo's body putting Dexter in danger of being caught. A boy is found who witnessed the crime.
The police identify the Ice Truck Killer. However Dexter feels there is something wrong with the suspect. Dexter must also deal with Paul, Rita's recently paroled husband.
Dexter suspects rich women's shrink of murder. When he visits the shrink, he is surprised by a dark secret from his past.
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.
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.
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 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.