The new addition to the ‘Dexter verse,’ Original Sin, further expands the lore that fans have long been familiar with. As the prequel series traces Dexter’s journey into becoming a ruthless killer, it continues to reaffirm just how unreliable he was as a narrator in the original series.
Beyond his recollections of characters like Harry and the origins of the ‘Code,’ the details surrounding his first kill, Nurse Mary, further emphasize how Dexter may have distorted the truth. The prequel sheds new light on this pivotal moment, suggesting that he may have bent the narrative more than he let on.

Revisiting Dexter’s first kill: A look back at the original series
Dexter: Original Sin revisits Dexter’s first kill early in its premiere episode, following Harry’s hospitalization due to a heart attack. The episode, titled And in the Beginning…, depicts him uncovering the dark truth about Nurse Mary, a character briefly mentioned in the original series.

Initially, the original series established that Nurse Mary was a serial killer who poisoned her victims with high doses of potassium nitrate. She was also responsible for attending to Harry, whose condition deteriorated under her care.
In a flashback, Harry is the one who identified Nurse Mary’s crimes, warning Dexter (Michael C. Hall) that she was poisoning him with morphine and an unidentified substance. Ultimately, Harry gave Dexter the green light to kill her before she could harm anyone else.
Original Sin revealed the true story behind Dexter’s first kill
Dexter: Original Sin further adds to the narrative, revealing the full truth of what happened. It’s not Harry who first noticed Nurse Mary’s sinister actions, but it was Dexter (Patrick Gibson) himself.
From smirking at the passing of a patient to collecting newspaper clippings of her victims’ memorial notices, Dex observes her and identifies her as a fellow traveler upon ultimately discovering the high levels of potassium nitrate in Harry’s doses.

Knowing he needed Harry’s approval, he carefully framed the situation to convince him. In this version, Dex tells Harry that the shots are killing him, prompting Harry to weakly utter, “Stop… her…,” effectively giving him permission for his first kill.
The distinctions between the two narratives have left many fans puzzled, with some calling it a continuity error. However, others believe this further proves just how unreliable of a narrator Dexter truly is.
Fans debate over the reliability of Dexter as a narrator from the original show
The discrepancies between the original series and the prequel have sparked debates among fans, particularly about Dexter’s reliability as a narrator. Some argue that the original show presented events only as he remembered them, potentially omitting or distorting key details, such as his first kill.
“In the original, you only see how Dexter recalls it,” one Reddit user said, suggesting that Original Sin depicts the actual events rather than Dexter’s flawed perspective.
Dexter Original Sin – Plot-line Mistake?
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The leading explanation for these differences is that Dexter likely misremembered events, a notion reinforced by various details, such as how Harry nurtured Dexter’s urges with the Code instead of seeking meaningful help for him.
However, it is also challenged by the show’s inclusion of moments involving Harry and Debra’s lives, details Dex himself may not have known, suggesting that the prequel might not be filtered through his perspective but instead presenting events as they truly happened.
Dexter and Dexter: Original Sin are available to watch on Showtime.
This post belongs to FandomWire and first appeared on FandomWire