The series blends drama, horror and black comedy as it follows the day-to-day events in the life of Dexter Morgan, a forensic blood spatter analyst for the Miami Metro Police Department who also happens to be a serial killer. He was taught by his adoptive father, Harry, only to kill those "who deserve it"; mainly, other killers who have escaped the legal system or were never suspected in the first place. The series shows him balancing an everyday life with his secret identity, all while keeping up a facade of normalcy.
Dexter's opening title sequence features an extended montage where ordinary day-to-day events such as shaving, flossing, dressing, preparing breakfast and eating are used visually to evoke Dexter's sinister nature. Per television critic Jim Emerson, "The first time you see it... it tells you everything you need to know about the character."
The series won an Emmy Award in 2007 for "Outstanding Main Title Design", while the title music was also nominated for "Outstanding Original Main Title Theme Music" in the same season. The title design and music were created by Digital Kitchen.
Orphaned at the age of three, Dexter Morgan was adopted by a Miami police officer named Harry Morgan. Harry recognized Dexter's sociopathic tendencies and taught him to channel his gruesome passion for thrill-killing towards people who deserve it. Dexter's victims must be killers themselves; people who have killed the undeserving (usually multiple times) with no remorse. He must also have proof that the criminals are guilty before he takes action.
Flashbacks throughout the series show how Harry, who died several years before, instructed Dexter in the art of appearing normal and covering his tracks. He follows Harry's instructions closely, calling them "The Code". Like many serial killers, Dexter keeps trophies from his kills; before dispatching a wrongdoer Dexter makes a small incision on their right cheek with a scalpel and collects a blood sample which he preserves between two glass slides. He stores his collection of blood slides in a box concealed inside his air conditioner.
Although his drive to kill is unflinching, Dexter is, through extensive instruction from Harry, able to fake normal emotions and keep up his appearance as a socially responsible human being. To hide in plain sight and to erase his own crimes, Dexter works as a blood spatter analyst for the Miami Metro Police Department. Dexter also uses his calculated charm to become well liked by all of his colleagues, except for a few who think something is odd about him.
Despite not having any "real" feelings, he feels affection towards Harry’s biological daughter and his adoptive sister, Debra. Debra makes her jealousy known of the perceived preferential treatment Harry gave Dexter, but is unaware of Harry's training or Dexter's tendencies. He also dates a woman named Rita in order to appear normal. Rita is psychologically damaged from past rape and abuse by her ex-husband, Paul, and is too distraught to want to be in an intimate relationship. This suits Dexter, who believes he is unable to fake intimate emotions. He also is fond of Rita’s two children, Astor and Cody.
"The Ice Truck Killer", a serial killer eluding the Miami PD, has been communicating with Dexter through his crime scenes. Sgt. James Doakes (Erik King) suspects that Dexter has some connection to the Ice Truck Killer and starts to keep him under surveillance. After repeated attempts to get back in Rita’s life, Dexter sets up Paul to look like he violated his parole. While back in prison proclaiming his innocence, Paul points Rita to a clue to the truth about Dexter, which she dismisses.
Debra begins dating a man named Rudy, who is later revealed to be the Ice Truck Killer. Rudy also reveals to Dexter alone that he is his biological brother, Brian Moser. He describes additional details of Dexter's early childhood to him. The formative event for the brothers was witnessing their mother and several other people being butchered by a drug dealer and being locked in a cargo container for two days with the dismembered corpses, the floor covered in blood. Brian spent much of his childhood institutionalized. Harry, the officer who freed the boys, deliberately hid the details about the crime from Dexter, as well as information about his biological family.
Brian kidnaps Debra with the intention that he and Dexter would kill her together to cement their bond and sever the ties between Dexter and his adoptive family. Dexter instead turns against Brian and ultimately kills him, making the death look like a suicide. Everyone, including Debra, remains unaware of the exact connection between Dexter and Rudy/Brian. Dexter feels some regret over killing Brian, the one person who fully understood him, in order to save Debra, whom he knows would turn away from him if she ever learned his true nature.
In the U.S., the complete first season of Dexter was released in a four-disc DVD package on August 21, 2007. On January 6, 2009, a three disc Blu-ray version was released.
Season 1 was an adaptation of Jeff Lindsay's first "Dexter" novel, Darkly Dreaming Dexter. Future Dexter seasons featured original storylines.
Dexter has been unable to satisfy his killing-urges for over a month, due to the constant surveillance by Sgt. Doakes. When the opportunity to kill arises, he has problems executing his victims after having killed his brother. Dexter struggles with his life as a serial killer thanks to him learning that Harry was sleeping with Dexter's biological mother, Laura Moser, before she died and that Harry took his own life after walking in on Dexter in the middle of a murder, unable to deal with the reality of the monster he had created. With his confidence in the Code of Harry and himself destroyed, Dexter plays out the possible resulting scenarios in his head of turning himself in.
Debra continues to struggle with the trauma of her experience with the Ice Truck Killer. For a sense of safety and comfort, she stays with her brother, another new source of stress in Dexter's life. To further complicate matters, treasure hunters discover Dexter's underwater dumping ground for his victims. As the police extract body parts from the ocean, the media dubs the killer the "Bay Harbor Butcher," and FBI Special Agent Lundy is brought in to catch him. A cult following begins to form behind the "Butcher" when it is discovered that his victims were themselves responsible for deaths.
Rita's relationship with Dexter becomes tense as she and her children deal with the death of her ex-husband Paul, who was killed in a prison fight. Paul's repeated suggestions that Dexter was to blame for his imprisonment cause Rita to finally accuse Dexter of setting up her ex-husband. Dexter admits to setting up Paul, but Rita refuses to believe that Dexter premeditated the crime and assumes that Dexter is a heroin addict. He admits to "having an addiction"; in return, she vows to stay with him while he goes through the Narcotics Anonymous program. There, he meets and becomes involved with his sponsor, Lila, a pyromaniac who starts to obsessively pursue Dexter.
Doakes confronts Dexter leaving an NA meeting. Doakes is temporarily satisfied that Dexter's odd behavior can be explained by traumatic experiences from a career in law enforcement and drug abuse. Doakes' suspicions about Dexter eventually return, and he ultimately discovers Dexter's glass slides. The possibility of matching them with the bodies of the Butcher's victims sets up a climactic showdown in which Doakes confronts Dexter at a remote cabin, ending with Dexter overpowering Doakes and keeping him locked in a cage inside the cabin. Dexter then begins framing Doakes as the Butcher after the police discover Dexter's slides in Doakes's car. Lieutenant LaGuerta, Doakes's former partner, is the only one who believes that Doakes is innocent. She finds evidence of this and takes it to Lundy, who rejects LaGuerta's case files.
In the season finale, Lila finds the cabin where Doakes is imprisoned and causes a propane tank explosion, blowing up both Doakes and the corpse of one of Dexter's victims, preventing Dexter from being caught. Lila then meets with Dexter, expecting him to accept her love now that she knows his "dark secret". She catches him preparing to kill her and seeks revenge by trying to kill Rita's children and Dexter. Dexter manages to save the children and escape, later exacting his own revenge on her after she has fled to Paris. In the closing scenes, Doakes' memorial service goes largely unattended, with the exception of LaGuerta, Dexter, and Doakes's immediate family.
Season 2 premiered on September 30, 2007. On July 17, the first two episodes of the season were leaked on the internet, and on December 4, the last two episodes were also leaked. On November 4, 2007, the Writer's Guild of America started a strike, but writer Daniel Cerone stated in the L.A. Times that Season 2 had already been completed in anticipation of the WGA's action.
The complete second season of Dexter was released in the USA and Canada on August 19, 2008. It was released in Australia and New Zealand on August 21, 2008. The season 2 Blu-ray was on May 5, 2009.
Rita discovers she is pregnant, informing Dexter that she will keep the baby and raise him with or without his help. He ends up proposing marriage to Rita, which she accepts.
While stalking a murderous drug dealer, "Freebo", Dexter stumbles upon a fight between Freebo and another man, whom he is forced to kill in self defense. This victim turns out to be Oscar Prado, brother of ADA Miguel Prado (Jimmy Smits) a prominent assistant district attorney and old flame of Lt. LaGuerta. Miguel comes to confide in and trust Dexter after he helps assist with the case.
Eventually, Dexter tracks down Freebo and kills him, but as he leaves he encounters Miguel, who has followed a lead to Freebo's location. Dexter tells Miguel he had discovered Freebo and killed him in self defense, but instead of reprimanding him, Miguel thanks him and offers to help him cover up the crime. As Dexter and Miguel cooperate to conceal Freebo's true demise from everyone else, the duo end up becoming close friends, as do Rita and Miguel's wife, Sylvia.
Later, Miguel discovers that Dexter killed a murderer he had complained about before. He praises Dexter for killing another criminal and offers his aid in the future. Trying to discourage Miguel, Dexter proposes a risky operation to free an infamous Aryan Brotherhood leader from prison in order to kill him. Miguel agrees with the idea and the plan succeeds. Dexter starts to recognize Miguel as his first and only true friend, to the point of inviting him to be his best man at his wedding.
Debra starts working more seriously to earn her detective shield, and also starts working with a new partner, Joey Quinn. They investigate a serial killer, "The Skinner", who has the habit of skinning his victims while alive. She also starts a relationship with Anton, one of Quinn's confidential informants.
Miguel and Dexter's partnership takes a new step when Miguel offers to be the one to kill their next target. With some reluctance, Dexter agrees, only watching as Miguel kills without hesitation. The next day, Ellen Wolf, a ruthless defense attorney and old courtroom adversary of Miguel's, goes missing, and Dexter discovers that Miguel has killed her alone. Dexter also learns that Miguel has been manipulating him since the beginning, having never trusted him at all.
The police investigate the death of Ellen Wolf and capture The Skinner. Dexter eventually realizes that Miguel cannot be allowed to run loose any longer, at which point Dexter decides to kill him and make it look like The Skinner did it. Meanwhile, Miguel uses his position to help The Skinner escape police custody in return for his agreeing to kill Dexter.
Striving to discover the truth about Ellen Wolf's death, LaGuerta ends up obtaining evidence which links Miguel to the crime. Miguel discovers that LaGuerta was investigating him and decides to kill her, but Dexter discovers Miguel's plot and captures him. Before killing Miguel, Dexter confesses to him that he was the one who killed Oscar.
After Miguel's body is discovered, he is immediately identified as a victim of The Skinner, just as Dexter planned. Miguel's other brother, Ramon, however, becomes suspicious of Dexter. After pointing a gun at Dexter during a dinner with Rita, he is taken into custody. During a visit to him in jail, Dexter helps Ramon put his demons to rest by relating himself to Ramon.
On the night before his wedding, Dexter is captured by The Skinner, but manages to break free by taking advantage of a moment when the Skinner is distracted, shattering his hand in the process. After a short but vicious fight, Dexter manages to snap The Skinner's neck and make it look like suicide by throwing his body before a running police car. Dexter gets his broken hand put in a cast and attends his wedding.
The complete third season of Dexter was released in the USA and Canada on DVD and Blu-ray on August 18, 2009.
Dexter is now a married family man, and Rita has given birth to a baby boy named Harrison. The family has moved to the suburbs, where Dexter struggles to reconcile his new life with his killing urges. Special Agent Frank Lundy returns to hunt down the "Trinity Killer" (John Lithgow) whom he believes always murders three people in a very specific sequence: a young woman in a bathtub, an older mother of two falling to her death, and a father of two bludgeoned to death.
Lundy begins working with Debra and shortly after, an unseen assailant shoots them both, killing Lundy. Afterwards, Debra is barred from working the Trinity case because the shooting is suspected to be the work of Trinity, making Debra a victim. Debra eventually discovers that Trinity was not the shooter, and she is put in charge of the case. Meanwhile, LaGuerta and Batista have renewed their relationship and, in danger of losing their jobs, decide to marry.
While investigating Lundy's data about Trinity, Dexter determines Lundy was killed because he had determined when and where Trinity would claim his third victim. Dexter stakes out the building, and witnesses Trinity bludgeoning a man on a security camera. Dexter follows Trinity to his home, where he is surprised to discover that Trinity is a family man named Arthur Mitchell. Using the alias Kyle Butler, Dexter attends the same church as Arthur and eventually befriends him. While investigating the reasons behind Arthur's crimes, Dexter learns how he manages to reconcile his family life with his killing urges and utilizes that knowledge to deal with his own issues.
Dexter visits Arthur at his home and discovers that he will be traveling to Tampa on another building project, which could be the start of another cycle. Dexter decides to make the trip with Arthur to ensure this doesn't happen. On the way, Arthur takes Dexter to his childhood home and reveals that at the age of ten, he spied on his older sister in the shower out of innocent curiosity. Startled by his presence, she slips in the shower, shattering the glass shower door and cutting open her femoral artery, causing her to bleed to death. His mother committed suicide and his father died soon after. Dexter realizes that Arthur compulsively murders groups of people that bear resemblance to those in his family, recreating their deaths each time.
During Thanksgiving at Arthur's home, Dexter learns that Arthur has been terrorizing his family, locking his daughter away in her bedroom and physically abusing his son. After Arthur attacks his son, Dexter is forced to restrain him. Arthur then goes to see a reporter who has been snooping around the Miami P.D., Christine Hill, who is revealed to be his illegitimate daughter.
Later Arthur kidnaps a boy while being pursued by Dexter. Dexter does some research and finds out that Trinity's pattern begins with the abduction and murder of a ten year old boy first; revealing Trinity's pattern actually cycles in groups of four with the boys always disappearing five days before the first bathtub death. Dexter locates where Arthur is holding the boy and arrives just in time to save him as Arthur escapes.
Debra begins to investigate and eventually arrests Christine after finding that she is Trinity’s daughter. However, Christine is released due to a lack of evidence. Christine secretly contacts Arthur, but he refuses to help her and instead forbids further contact. Arthur also reveals his disdain for her having killed Frank Lundy, which she did to protect her father. Realizing the error of her ways, Christine confesses to Debra. Distraught, Christine seeks forgiveness from Debra, which she refuses. Christine then pulls out a gun and commits suicide in front of her.
One of Harry's old informants takes Deb to the house of Laura Moser. Deb immediately recognizes the house as the home of Brian Moser, the Ice Truck Killer. After piecing together Dexter's connection to Brian and Laura, Deb reveals this information to Dexter, explaining that Laura was his mother and Brian his brother. Dexter feigns surprise, stating that Brian must have tried to get to him through Deb.
Dexter decides that he must draw police attention away from Arthur, so he finds a man whom he can kill and pin the blame on. He then plants evidence and kills the man. Arthur lures Dexter to an arcade where he previously stalked victims and follows Dexter back to the police station, where he learns Dexter's true identity. Soon after, Dexter tails Arthur, but sideswipes a car on the way. Dexter captures and drugs Arthur, but the driver of the damaged car has found Dexter's car, called the police, and in the ensuing confrontation, Dexter is taken in by the police for leaving the scene of an accident and fighting with the driver in the presence of the police. By the time Dexter is released due to cell overcrowding, Arthur is gone from where Dexter had left his unconscious body.
Dexter eventually tracks down Arthur, capturing and bringing him to the bomb shelter where he held the missing boy. Dexter kills Arthur with a hammer and dumps the body. He returns home and picks up a message from Rita. After listening to the message, he decides to call her back. He hears Rita's phone ring from within the house and soon after, he hears Harrison crying. He rushes to the bathroom, where he finds Harrison sitting on the tile floor in a pool of blood while Rita lies dead in the bathtub, ostensibly having been murdered by Arthur.