How a Wrong-Place-Wrong-Time Revelation Led to the Downfall of One of ‘Dexter’s Best Characters

It was bound to happen sooner or later. There’s only so long you can hide being a serial killer from your adoptive sister … especially when that sister grows up to become a homicide detective. At least, that’s what Dexter told us.

A fan-favorite character

Dexter obviously centered around the titular character of Dexter Morgan but his sister Deb was a major favorite among fans.

Debra Morgan was born to Doris and Harry Morgan, and became Dexter’s adoptive sister after the family rescued him from a shipping yard when he was a child. Dexter and Deb’s relationship was close, but massively one-sided. Deb loved her big brother, and always tried to follow in his footsteps. She was also envious of her father’s perceived favoritism of Dexter due to how much time alone with his adoptive son. If only she knew the real reason why Dexter was cold and emotionally distant, why Dexter’s dad worked with him every day, and the real reason why her dad confiscated her beloved childhood puppy. Short answer: because Dexter is a psychopath.

After Harry Morgan’s death. Deb decided to follow in the footsteps of the legendary police officer and enter into the force herself. She rose through the ranks quickly and became a promising homicide detective with a penchant for swearing. F*ck yeah! She cracked many a serial killer case in her decorated career, but there was one killer she was never able to identify: The Bay Harbor Butcher. Until one day… she discovered who he really was.

How did Deb find out about Dexter?

Deb spends the sixth season of Dexter on the hunt for The Doomsday Killer, a religious serial killer named Travis Marshall who believes that his murders would help immanentize the eschaton. In non-religious speak: He thought killing people would end the world, exactly the way God intended. What Deb doesn’t know is that her brother Dexter is hunting for the same man and is prepared to use any and all means to find and deal with him.

Dexter is eventually able to capture the illusive Travis and take him to a “kill room,” one of Dexter’s pre-prepared murder spots with an interior design theme of “karmic justice.” This one happens to be in a church, how poetic. Travis awakens bound, and Dexter begins to converse with him, as he does with all his victims. He raises a blade to Travis’ chest and pushes it inside, unaware that Deb has tracked Travis’ location to this very place and is currently watching Dex do the deed from the wings. Oops. How’s that for a season finale?

So what happens next? A trip to the authorities?

Hardly. A stunned Deb draws a gun on Dexter and interrogates him about what she just saw. Dexter manages to convince Deb that Travis had intended him to be his next victim, and that Dexter “snapped” in self-defense. He goes on to convince her that her best course of action is to help him dispose of the body. Deb agrees and the pair torch the church with gasoline. When the homicide team shows up the next day, they see Travis’ favorite edged weapon The Sword of Saint John the Revelator stuck in his chest. They rule the death as a suicide, but some people on the team suspect that the Bay Harbor Butcher is still alive and kicking.

Debra realizes this too. Eventually, she discovers Dexter’s kill tools and the many trophies that he has taken from his victims. Rather than follow the direction of her moral compass, she decides to chuck it out the window and continue to cover for Dexter. Or perhaps rather, she reorients it. After seeing that Dexter is targeting the psychotic serial killer Ray Speltzer who once attacked her, she reasons that her brother is actually making the world a better place by ridding humanity of its worst. Eventually, she went so far as to kill an innocent woman to cover up for Dexter’s crimes. It was pretty much Dexter’s fault, and he felt some species of guilt Deb’s action, but he continued to accept her help.

Debra’s guilt about her knowledge (and participation) in Dexter’s crimes eventually proved to be her undoing. She quit the police force and started drinking to cope. She was eventually able to reconcile with her brother after the shooting, but their sweet reunion was short-lived… but that’s a spoiler for another time.