Dexter Morgan, a blood spatter pattern analyst for Miami Metro Police Department who also leads a secret life as a serial killer.
Forensic analyst Dexter Morgan hides his double life as a vigilante serial killer from his vice squad officer sister, his co-workers at the Miami Metro Police Department, and his commitment-minded single-mum girlfriend.
Dexter's world is rocked when a rival serial murderer, dubbed the Ice Truck Killer by the media, privately contacts him and reveals that he knows Dexter's grisly secret. Meanwhile, Dexter's sister Debra is transferred to Homicide.
Dexter and Debra try to dissuade their boss from pursuing a security guard they believe he has wrongly identified as the Ice Truck Killer. Meanwhile, Dexter's girlfriend receives an unwelcome visit from an associate of her imprisoned husband.
The Ice Truck Killer begins leaving body parts from his victims at sites that relate to memories from Dexter's childhood, forcing him to confront his dark personal history.
The Homicide Division is buzzing after the Ice Truck Killer's latest victim is found mutilated but alive, while Dexter gets in over his head when he stalks a murderous human trafficker.
The Ice Truck Killer leaves Dexter a surprise at the scene of one of Dexter's recent kills, placing him firmly in the cross hairs of his own Homicide Division colleagues.
The Ice Truck Killer is finally identified, but something about the suspect doesn't sit right with Dexter, who must also deal with the menacing return of Rita's paroled ex-husband.
The strange suicide of a powerful woman leads Dexter to suspect her shrink of murder, but he gets a shock when a visit to the suspect opens up dark secrets from Dexter's past.
Dexter is joined by Rita, Debra and Rudy for a weekend away when he learns that his biological father - whom he was told died thirty years ago - has just recently passed away and left him everything he owned, including his house.
The Ice Truck Killer leaves Dexter the most horrifying crime scene imaginable, forcing him to confront a horrific suppressed memory from his past. Meanwhile, Rita must hire a lawyer when her ex sues for sole custody of their children.
The Ice Truck Killer kidnaps someone close to Dexter, forcing him into a trap that will forever change his life, while Doakes begins to harbour suspicions about Dexter's odd behaviour.
Dexter follows the clues left for him by the Ice Truck Killer in an effort to rescue his kidnapped loved one, while Rita's ex tries to convince her that Dexter is too dangerous to be around their children.
Dexter finds himself unable to kill again after the harrowing conclusion to the Ice Truck Killer case, and strays from his personal code with disastrous results. Debra returns to work but may not be ready.
Dexter remains on the trail of a dangerous new victim, while the traumatized Debra loses control on the job. A high-profile FBI agent arrives in Miami to investigate a newly discovered serial killer - the Bay Harbour Butcher.
Dexter's sudden inability to deceive has him pursuing a slick liar as his next victim, while Rita believes he's concealing a drug problem and forces him into a 12-step programme where he meets the seductive Lila.
Rita finds herself threatened by Dexter's sexy new Narcotics Anonymous sponsor Lila, plus stressed by a visit from her estranged mother. Dexter tries to throw the dogged, intelligent FBI Agent Lundy off his bloody trail.
Dexter discovers that the man is still alive who murdered his mother in front of him as a boy, and confronts the killer as part of his recovery from addiction - but he also discovers that old impulses die hard.
A new copycat killer openly mimics and claims to be inspired by the Bay Harbour Butcher, driving the annoyed Dexter into the arms of Lila - a development that could spell the end of his relationship with Rita.
A written manifesto from the Bay Harbour Butcher sends the task force in charge of capturing him into chaos, which is part of Dexter's plan for keeping Lundy off his trail.
Dexter decides that Lila is becoming too attached, decides 'recovery' isn't working for him, and pays another visit to his mother's killer. Debra and Lundy find a clue that points to the Bay Harbour Butcher being right under their noses.
Dexter tries to distance himself from Lila but discovers she is not so willing to let go of their relationship. Lundy's manhunt makes Dexter nervous as he tries to stay one step ahead - but it's Dexter's worst enemy that learns his secret.
Dexter's world comes crumbling down when Doakes tracks him to the scene of his latest kill and reveals a devastating secret about Harry. The Miami Metro PD closes in on the Bay Harbour Butcher.
Dexter dodges bullets both figurative and real as he is forced to decide the fates of those he cares about most. Lila attempts to blackmail Dexter and makes a startling discovery that changes the nature of their relationship.
Lundy and the FBI settle the case of the Bay Harbour Butcher once and for all but the heat's not entirely off Dexter as his world literally becomes an inferno. Can he rise from the ashes once again?
Dexter's life seems to be smoothly back on track, until he targets a dope dealer who is also in the sights of Assistant D.A. Miguel Prado. Internal Affairs pressures Debra to rat on her new partner.
Every cop in Miami is tasked with finding the fugitive Freebo who is accused of killing the younger brother of Assistant D.A. Miguel Prado. Dexter and Rita move closer to making a big decision about their family.
Dexter encounters a fellow predator - but this one is a paedophile. A murder is pinned on Freebo, but Dexter knows the truth and struggles with the fact of his growing friendship with Assistant D.A. Miguel Prado.
Dexter scrambles to convince Rita that his marriage proposal is sincere and romantic. Meanwhile, Miguel's vengeful brother Ramon searches desperately for their sibling's murderer - who was secretly killed by Dexter.
Dexter hears the story of a husband who has gotten away with murdering two wives for financial gain and tracks the man to Bimini, but Rita has a medical emergency while Dexter is nowhere to be found.
Dexter tests Miguel to determine if his friend has discovered his secret, while Rita loses her job and wonders if she's meant to ever have a successful career.
Dexter begins working with Miguel but they quickly have differences in selecting a potential new victim. Rita discovers that Miguel's wife suspects him of an affair, and an old friend of Dexter's asks for help in ending her life.
Dexter undertakes to teach Miguel the 'code', but doesn't realise he's whetting his partner's thirst for blood. Debra is one step closer to finding the Skinner but a secret revealed about Anton sends him packing.
The friendship between Dexter and Miguel becomes strained even as Rita revolves to confront Miguel about his suspected infidelity. Debra searches furiously for Anton when it's revealed that he was abducted by the Skinner.
A series of chess-like moves ensues when Dexter and Miguel vie for the upper hand, with Miguel winning Rita's affection by presenting her with a lavish wedding gift. Debra, meanwhile, wonders if her relationship with Anton is worth the trouble.
Dexter must find a way to get rid of Miguel despite the fact that his friend is a highly placed district attorney, and Dexter's best man. Rita discovers that Miguel has been seeing an old flame, and Debra finds a new clue to the Skinner's identity.
Dexter attempts to calm the emotionally unstable Ramon now that Miguel is out of the picture. Debra is about to receive her detective's shield but is blind-sided with information that could derail her promotion.
Dexter sleeplessly struggles to balance his new family life with his dark, murderous drive for a fresh victim, and his busier-than-ever forensic career pursuing a new target, the Trinity Killer.
Dexter realises that he has carelessly misplaced crucial evidence that could expose his dark side to the world, while helping to investigate new slayings that Agent Lundy insists are the work of Trinity.
Dexter is hampered by his neighbourhood's increased vigilance due to vandalism, his temporary inability to drive himself anywhere, and his admiration for the killing technique of the artful Trinity Killer.
Dexter gets some much-needed R&R time with Rita and the kids out of town, leading to his stalking of a new victim; until he unexpectedly begins to empathise with his target: a cop that murdered her family.
Dexter is inspired to investigate the Trinity Killer on his own, while Debra blames herself for an event that was out of her control, and Rita realises how little she knows her husband after discovering one of his secrets.
Dexter doubles his efforts to stay ahead of the official Trinity investigation, and receives relationship advice about the friction between himself and Rita from a most unexpected source.
Dexter finally strikes a balance between family, career and his secret life, but is thwarted in his pursuit of his next victim. Debra, meanwhile, expresses a renewed and unwelcome interest in their father's chequered past.
Dexter wonders if his father's 'code' is truly the right path and hopes to get answers by accompanying Trinity on an out-of-town road trip. Debra, meanwhile, discovers that her single-minded pursuit of Trinity has blinded her to the truth.
Dexter learns more about Arthur's bizarre and twisted world, while Rita has her hands full preparing Thanksgiving dinner for a full house. Debra uses the holiday to further investigate Trinity, and Batista gets closure on an old case.
The disappearance of a ten-year-old boy forces Dexter to question his assumptions about Trinity, while Cody defends one of Dexter's lies and Masuka is unable to face what he witnessed on Thanksgiving.
Dexter must buy time to protect himself when Debra's investigation brings the department one step away from identifying Arthur as the Trinity Killer. Rita confides in Dexter, but is disappointed in the result.
Dexter and Arthur find themselves on a collision course. As Debra unearths a shocking long-hidden truth, Rita admits her marriage to Dexter is troubled, and Batista and LaGuerta face the consequences of an ethics breach.
Dexter reels from Rita's murder and makes a choice that will affect everyone's lives. Quinn stirs up trouble by suggesting that Rita's death doesn't fit Trinity's profile and offers much-needed support to Debra.
Dexter tries to focus his energy on his kids and fight his dark urges, but a shocking discovery puts him on the trail of a new victim. Debra hosts her brother and his children but finds herself squeezed out of her own place, and ends up on Quinn's doorstep.
In an effort to create more free time to stalk and kill his victims, Dexter hires a nanny. Debra is annoyed by her new partner, a rookie with her own theories on a bizarre double homicide. Quinn, meantime, pursues the theory that Trinity did not kill Rita.
Dexter hunts a new target, but is distracted and drawn into a precarious situation while helping his troubled acquaintance. Batista discovers an interesting lead in the Santa Muerte murder cases; Quinn learns some new information about Dexter from a questionable source.
Dexter is saddled with an unwanted conspirator; Dexter worries about how Rita's death will affect Harrison; Deb works alone; Quinn enlists an old friend's help.
Saddled with an unwanted conspirator, Dexter is forced to make some hard decisions about her fate. Meanwhile, Dexter wonders if Rita's death has awakened a darkness inside Harrison, and Debra works the Santa Muerte cases alone.
While helping Lumen, Dexter finds himself on a collision course with Debra and the rest of Homicide when he is called to investigate a horrifying crime scene; Moreover, the Santa Muerte case leads to a violent standoff between Debra and the killers.
While attending a self-help seminar, Dexter and Lumen vet and stalk a violent killer. Debra, meanwhile, gets into some unexpected trouble from the fallout of the Santa Muerte case, forcing Batista to make a difficult decision.
While in the midst of hunting down their next victim, Dexter and Lumen are surprised by the return of an unannounced guest. Assigned to the file room, Debra still manages to uncover new evidence in the Barrel Girl case.
Dexter discovers a possible ally in the pursuit of Lumen's former captors, but he and Lumen are forced to step down when Homicide uncovers evidence linked to one of their prior victims.
Dexter is forced to do damage control after he concedes that someone outside of Miami Metro has taken an interest in him and Lumen. Debra's speculation on the missing Barrel Girl suspects begins to take shape, and Quinn becomes more involved in a homicide than he'd like
Dexter realises that he and Lumen are being lured into a trap and risks everything to escape. While Debra lets her personal feelings overwhelm her instincts in the Barrel Girls case, Quinn finds himself in need of help that only Dexter can provide.
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.
Brother Sam, a minister with a criminal history, is brought in by Homicide 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 confronted with a sobering glimpse of his own potential future when a serial killer from his past makes a reappearance. Travis struggles to keep his mentor happy as he and Gellar prepare a new twisted tableau, ensuring Debra's next task will be a daunting one.
Much to his surprise, an emergency with Harrison and a new tableau from Gellar and Travis has Dexter leaning on Brother Sam and an unexpected winged messenger as he questions the idea of faith.
With the help of his newfound friend Brother Sam, Dexter wonders if there is light within him to counter the darkness, while the search for the Doomsday Killers takes him in a new direction. Meanwhile, Batista and Quinn visit the university where Prof. Gellar taught.
Dexter is caught up in a very personal case that awakens the needs of his Dark Passenger. Debra feels overwhelmed by her new Lieutenant duties, made all the more complicated when she finds out Quinn slept with a witness in the Doomsday case.
Dexter finds himself teamed up with a fellow Dark Passenger when he takes a road trip to Nebraska to tie up some loose ends from the past. Meanwhile, Debra deals with the complications of her promotion as she leads the Doomsday investigation.
While Dexter uses lessons he learned from Brother Sam to follow up on some new leads in the Doomsday investigation, Debra butts heads with Captain LaGuerta over the case of a dead call girl.
While Dexter receives help from an unexpected source in hunting the Doomsday Killers and staying one step ahead of Homicide, Debra discovers something new about herself in therapy.
Dexter tries to figure out the Doomsday Killers' next victim before it's too late. Elsewhere, Debra has a strong reaction to a crime scene, which leads her to the realisation that she leans too heavily on her brother.
Dexter finds that in order to catch the Doomsday Killers, he must create a macabre tableau of his own. Debra's battle with LaGuerta over the case of the dead call girl boils over, and her therapist makes an unnerving suggestion.
Dexter and Homicide race against a lunar eclipse to catch the Doomsday Killers before their final gruesome act; Debra struggles with a new emotional reality.
Reeling from Debra witnessing Dexter kill Travis Marshall, brother and sister attempt to reconcile while struggling to cover up their involvement with the murder. Elsewhere, LaGuerta finds evidence that causes her to re-think the closed Bay Harbour Butcher Case.
When a local convict claims he has new information regarding a fifteen-year-old crime spree, Miami Metro sets out to unearth new evidence on the case. While Debra attempts to cure Dexter of his killer tendencies, the Mike Anderson case leads to the Ukrainian mob.
Dexter tries to bring Debra on-board with his new target while the Ukrainian mob seeks revenge for the killing of one of their own. Quinn grows close to a dancer at the mob's strip club, and LaGuerta seeks Batista's help in getting the Bay Harbour Butcher case reopened.
After capturing a deadly killer, things go awry for Miami Metro, sending Debra into a tailspin. In an effort to help his sister, Dexter enters into a dangerous game of cat and mouse while the Ukrainian mob continues to seek revenge.
While trying to uncover why Louis was killed on his boat, Dexter must out-manoeuvre Isaak, who is after Dexter - and Debra. New leads are brought to light on the Wayne Randall killing spree case by his former accomplice, Hannah McKay, who Dexter discovers has a secret.
Dexter becomes more intrigued by Hannah, while Debra gets to know local crime writer Sal Price, who has dug up some possibly incriminating dirt on Hannah. And try as she might, Debra can't stop LaGuerta from upending the Bay Harbour Butcher case…
Things heat up as Dexter and Hannah grow closer, and when Sal Price discovers the two are involved, he wants the exclusive story. Sal helps Debra uncover new evidence about Hannah while Quinn makes questionable choices to protect his girlfriend, Nadia.
Dexter tries to keep Debra in the dark about his relationship with Hannah but a surprise visit from Astor, Cody and Harrison throws a wrench into his plans. Now out of jail, Isaak renews his pursuit of Dexter while Quinn continues his power struggle with the Koshkas.
Dexter is preoccupied with Isaak still on the loose, but an internal struggle within the Koshka Brotherhood could work to Dexter's advantage. While Miami Metro is on the hunt for a phantom arsonist, Dexter goes to great lengths to protect his relationship with Hannah.
A visit from Hannah's father puts Dexter on alert, and the Phantom Arsonist's crimes become more gruesome. Defending Nadia's honour forces Quinn into a dangerous situation, and LaGuerta brings on former Deputy Chief Matthews to help with the Bay Harbour Butcher case.
As Christmas approaches, Dexter tries to balance his life with Hannah and his relationship with Debra. However, when Dexter learns that the man responsible for ordering his mother's death has been released from prison, he zeros in for a kill that might end all kills.
As LaGuerta closes in on Dexter's secret, Dexter struggles to protect himself, Debra, and the life he's built.
It's been six months since LaGuerta's murder and Dexter is still managing life as a dad, brother, and serial killer. Debra now works as a P.I. and Batista has replaced her as Lieutenant. Miami Metro investigates a murder where the victim had pieces of his brain removed.
Miami Metro continues their hunt for the Brain Surgeon while Dr. Vogel enlists Dexter to do her bidding based on her own personal experience with her previous patients. Debra continues to track down her P.I. case and has to take matters into her own hands.
Dexter continues his manhunt for the Brain Surgeon. Dr. Vogel tries to prove to Dexter that he's perfect as a psychopath. Debra's PTSD kicks in and she makes a desperate plea to confess to LaGuerta's murder.
Dexter tracks down another potential serial killer from Dr. Vogel's list. Quinn celebrates his passing of the Sergeant's exam by defending Debra's honour in a fight. Dr. Vogel begins treating Debra for her PTSD.
Dr. Vogel gets abducted by the Brain Surgeon and Dexter and Debra try and rescue her. At the same time, Masuka finds out he has a daughter.
Dexter monitors a young psychopath to see if he is suited for his table. Dexter and Debra finally get back to normal but are surprised by his ex, Hannah.
Dexter hunts down Hannah to figure out why she's back in Miami. Dexter also takes on a protégé and starts teaching him the 'code'.
Dexter tracks down his protégé in the belief that he murdered his neighbour. Meanwhile, Dexter tries to help Hannah escape the country.
Dexter investigates the murder of his protégé, while Dr. Vogel gets the surprise of a lifetime when someone returns from her past.
With help from Dr. Vogel, Dexter tries to lure the Brain Surgeon to a location in order to get him on his table. In the end, an important person in Dexter's life is murdered before his eyes.
Dexter is torn between fleeing the country with Hannah and Harrison and taking Saxon out once and for all. A dramatic sequence of events follows that shows Dexter's growth as a human being, but at the same time his lack of action causes a grizzly end to the episode.
In the final episode of this groundbreaking series, Dexter is faced with impossible odds. A brewing hurricane is about to touch down on Miami and Dexter has to end things his way.
