Dexter Morgan, a blood spatter analyst for the Miami Metro Police Department, leads a double life as a vigilante serial killer. The series opens with Dexter narrating his life, revealing his dark urges and the code he follows, taught to him by his adoptive father, Harry Morgan. Harry's code dictates that Dexter only kill those who have escaped justice, targeting other killers.

In the first episode, "Dexter," we see Dexter at work, analyzing a crime scene involving a gruesome murder. He is emotionally detached, showcasing his ability to compartmentalize his life. He interacts with his sister, Deborah Morgan, a police officer who is eager to prove herself in a male-dominated environment. Dexter's relationship with Deborah is complex; he cares for her but struggles to connect emotionally.

The narrative shifts to a new case involving a serial killer dubbed the "Ice Truck Killer," who is leaving bodies drained of blood and meticulously arranged. Dexter becomes fascinated by the killer's methods, feeling a connection to the artistry of the murders. He begins to investigate the case, using his skills to analyze the crime scenes.

As Dexter delves deeper into the investigation, he meets Rita, a woman with two children who is trying to escape an abusive relationship. Dexter is drawn to her vulnerability and begins a romantic relationship, which complicates his life further. He struggles with his feelings for Rita and his need to kill, trying to maintain a façade of normalcy.

The Ice Truck Killer continues to taunt the police, leaving clues that lead Dexter to believe he knows the killer's identity. Dexter's investigation reveals that the killer is targeting people who have committed heinous acts but escaped punishment. This resonates with Dexter's own motivations, and he becomes increasingly obsessed with the case.

In a pivotal moment, Dexter discovers that the Ice Truck Killer is actually his biological brother, Brian Moser. This revelation shakes Dexter to his core, as he grapples with the implications of having a sibling who shares his dark tendencies. Brian reaches out to Dexter, attempting to draw him into his world of killing, which creates a moral conflict for Dexter.

As the tension escalates, Brian kidnaps Rita and her children, using them as leverage to manipulate Dexter. In a desperate attempt to save them, Dexter confronts Brian in a warehouse. The confrontation is intense, with Dexter torn between his loyalty to his family and his dark urges. Brian tries to convince Dexter to embrace his true nature, but Dexter ultimately rejects him.

The climax occurs when Dexter manages to rescue Rita and her children, but not without a violent struggle. He kills Brian in a moment of rage, fulfilling his need to eliminate a threat while also confronting the reality of his own nature. This act leaves Dexter feeling conflicted; he has killed his brother, a reflection of himself, which deepens his internal struggle.

In the aftermath, Dexter returns to his life, but the emotional toll of the events weighs heavily on him. He continues to navigate his relationships with Rita and Deborah, who remain unaware of his true identity and the darkness within him. The season concludes with Dexter reflecting on his actions, hinting at the ongoing battle between his desire for connection and his need to kill.

At the end of "Dexter" Season 1, Dexter Morgan confronts his dark urges and the consequences of his actions. He faces off against the Ice Truck Killer, who is revealed to be his biological brother, Brian Moser. The season concludes with Dexter making a pivotal choice that impacts his relationships and his own identity.

As the final episode unfolds, the tension escalates. Dexter Morgan, a forensic blood spatter analyst for Miami Metro Police, has been tracking the Ice Truck Killer, who has been leaving a trail of gruesome murders. The killer's identity is finally revealed to be Brian Moser, Dexter's biological brother, who has been orchestrating a series of killings that resonate deeply with Dexter's own dark tendencies.

In a gripping scene, Dexter finds himself in a confrontation with Brian in a secluded location. The atmosphere is thick with tension as the two brothers engage in a conversation that reveals their shared past and the trauma that shaped them. Brian, who embodies the darker aspects of Dexter's nature, tries to persuade Dexter to embrace his violent instincts fully. The emotional weight of their familial bond hangs heavily in the air, as Dexter grapples with the implications of their connection.

As the confrontation escalates, Dexter is faced with a critical decision. He realizes that Brian's methods are not just a reflection of their shared blood but also a dangerous path that could lead to his own destruction. In a moment of clarity, Dexter chooses to reject Brian's influence. He ultimately kills Brian, a decision that signifies a turning point for Dexter. This act is not just about survival; it is a rejection of the darker path that Brian represents.

Following this intense climax, Dexter returns to his life, but the aftermath of his actions weighs heavily on him. He is left to navigate the complexities of his relationships, particularly with Rita, his girlfriend, and her children. The season closes with Dexter reflecting on his duality--his role as a vigilante who seeks justice for the victims of violent crime, while also grappling with his own dark urges.

In the final scenes, Dexter is seen in his apartment, contemplating the choices he has made. The camera lingers on his face, capturing the conflict within him. He is both relieved and burdened by the weight of his actions. The season ends with a sense of ambiguity, leaving viewers to ponder the implications of Dexter's choices and the path that lies ahead for him.

As the credits roll, the fates of the main characters are sealed: Dexter has eliminated the immediate threat posed by Brian, but the emotional and psychological ramifications of his actions linger. Rita remains unaware of Dexter's true nature, and the tension in their relationship is palpable. The season concludes with Dexter still on his journey, a complex character caught between his desire for justice and the darkness that resides within him.

In the first season of "Dexter," there are no post-credit scenes following the episodes. Each episode concludes with the standard credits, and the narrative wraps up without any additional scenes after the credits roll. The focus remains on the unfolding story of Dexter Morgan, his life as a blood spatter analyst for Miami Metro Police, and his secret life as a vigilante serial killer. The season builds tension and character development throughout its episodes, but it does not include any post-credit sequences.

Dexter Morgan is a blood spatter analyst for the Miami Metro Police Department.

Dexter's sister is Deborah Morgan, a detective with the Miami Metro Police Department, who is often involved in the investigations that Dexter secretly manipulates.

Dexter follows a 'Code' taught to him by his adoptive father, Harry Morgan, which dictates that he only kills those who are guilty of murder and have escaped justice.

The Ice Truck Killer is a serial killer who targets victims in Miami and has a personal connection to Dexter, as he is revealed to be Dexter's biological brother, Brian Moser.

Rita is Dexter's girlfriend, who is unaware of his dark secret, and she has two children from a previous marriage, which adds complexity to Dexter's life.

"Dexter," season 1, produced in 2006, is not considered family-friendly due to its mature themes and graphic content. The show revolves around Dexter Morgan, a forensic blood spatter analyst for the Miami Metro Police Department, who leads a double life as a vigilante serial killer.

Potentially objectionable or upsetting scenes and aspects include:

1. Graphic Violence: The show features scenes of murder and bloodshed, including depictions of Dexter's killings, which are often shown in detail.

2. Murder and Crime: The central theme involves serial killing, with various characters being victims of violent crimes.

3. Dark Themes: The narrative explores themes of morality, justice, and the psychological aspects of a killer, which may be unsettling.

4. Adult Language: The dialogue includes strong language and adult conversations that may not be suitable for younger audiences.

5. Sexual Content: There are scenes that involve sexual situations and adult relationships, which may be inappropriate for children.

6. Psychological Tension: The show often creates a tense atmosphere, dealing with the mind of a killer and the impact of his actions on those around him.

Overall, "Dexter" is intended for mature audiences and contains numerous elements that could be distressing for children or sensitive viewers.