Warning! This article contains SPOILERS for Dexter: Original Sin season 1, episode 10.The ending ofDexter: Original Sinseason 1 featured plenty of plot twists, intense moments, and happy conclusions, but so much happened in theDexterprequel that it’s worth explaining.Original Sinepisode 10 found a way to tie all of the season’s massive developments together in a satisfying way. Dexter (Patrick Gibson) got to catch and kill thekidnapper Aaron Spencer (Patrick Dempsey), and Harry Morgan (Christian Slater) got a chance to confront theNHI Killer, Brian Moser (Roby Attal). Debra (Molly Brown) also made a massive life decision at the end ofOriginal Sin, and the pieces of the original show mostly fell into place.
After Harry, Dexter, and Deb all overcame their challenges,Dexter: Original Sinshowed a bit of how their decisions panned out. Dexter and Harry were both very excited to learn that she was joining the police academy, and Dexter also got a full-time position as a forensic technician at Miami Metro. Harry, however, burned a bridge between himself and Maria LaGuerta (Christina Milian), though he did get to see his partner, Bobby Watt (Reno Wilson) survive his gunshot wound. There were quite a few happy endings inOriginal Sin, but the path to get there needs a bit more explanation.

Dexter Isn’t Really An Emotionless Monster & He Empathized With Nicky More Than He Wanted To Kill Spencer
Dexter usually asserts that he’s an emotionless monster, but when Dexter confronted Aaron Spencer, the police captain began drowning Nicky. Despite how much he wanted to kill Spencer, Dexter decided to save Nicky’s life instead, even though he almost let Spencer go in the process.A big reason Dexter chose to save Nicky is because he empathized with the boy, and he was deeply troubled by any violence against children. It’s the same reason he let Spencer go inOriginal Sinepisode 9: Dexter wanted to protect Nicky more than he wanted to kill Spencer.
He’s certainly a serial killer and a bad person, but Dexter is still human, no matter what he tells the audience.

Dexter himself had experienced enormous trauma when he was a little kid, and though he wasn’t aware of it inOriginal Sin, it affected him as an adult. Dexter likely saw himself in Nicky, and he jumped at the opportunity to save his life.Original Sinalso gave Dexter that chance to save a life instead of taking one because Dexter isn’t really a monster. He’s certainly a serial killer and a bad person, but Dexter is still human, no matter what he tells the audience. When Nicky’s life was on the line, Dexter’s human side won out over his “Dark Passenger.”
Why Brian Agrees With Harry That He Wasn’t Good For Dexter
One of the more shocking surprises in the season finale ofOriginal Sincame from Harry’s final showdown with Brian Moser (Roby Attal). Harry eventually told Brian “you may hate me for good reasons and still know that I am the best thing for Dexter.” Harry’s words managed to convince Brian, as Brian knocked him out and wrote “You’re right” on the wall in his blood.Brian had been watching Dexter for a long time, and he clearly realized that Dexter really did have a good life as Harry’s son. Harry truly loved Dexter, and Dexter enjoyed his semi-normal family, so Brian agreed to leave him be.
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The first time Brian tried to contact Dexter - at the restaurant inOriginal Sinepisode 2- Brian realized that Dexter didn’t recognize him anymore.Dexter had managed to block out all the traumatic memories of Laura and Brian, and Brian realized that reconnecting with his little brother would only bring those painful memories back. Though he was obsessed with Dexter, Brian also loved him, and he knew that letting Dexter live in blissful ignorance was better than making him relive the trauma of his mother’s death.

Spencer Knew About Harry’s Affair With Laura Moser, But Dexter Assumed He Was Just Lying
Image via Paramount+
After letting Spencer go, Dexter was able to quickly track him down at the house of Spencer’s ex-wife, Becca (Amanda Brooks).Dexter knew that Spencer was ruled by his rage and too angry to do the logical thing and flee, so he was able to save Becca’s life. Spencer is, in many ways, a parallel to Dexter. Spencer was completely fueled by rage and his violent impulses after his divorce from Becca, and he threw all logic and compassion out the window. He was a vision of what Dexter could be withoutthe Code of Harry: a monster who acts on his every urge with no regard for who gets hurt.
Spencer knew all the dirty details of Harry’s affair with Laura and how Harry’s involvement had made her a target of the cartel, and he was likely going to tell Dexter about all of it.

Once Dexter had Spencer on Camilla Figg’s boat, theSlice of Pie, they got a chance to briefly talk. Spencer told Dexter that Harry had “failed” him, but Dexter confusingly didn’t follow up on that claim before cutting into Spencer’s throat. Spencer knew all the dirty details of Harry’s affair with Laura and how Harry’s involvement had made her a target of the cartel, and he was likely going to tell Dexter about all of it.Dexter, however, probably assumed Spencer was lying through his teeth, as he had done so many times before, and dismissed the chance to learn Harry’s darkest secret.
Harry’s Decision To Tell Dexter He Was Born A Monster Explained
Harry Thought The Lie That Dexter Was Born A Monster Was Better Than The Truth That Would Destroy His Father Figure
At the end ofOriginal Sinseason 1, episode 10, Harry and Dexter debriefed about everything that had happened to them. Dexter told Harry about Spencer and how he saved Nicky’s life, and he lamented how Spencer became a monster while he himself was born a killer.Harry didn’t correct him, though, because he was still trying to save Dexter from living with the memory of Laura’s death. He had just convinced Brian to stay away to protect Dexter’s “innocence,” so Harry wouldn’t just change his mind and tell the truth.
Harry’s decision boiled down to one choice. If Harry told the truth, Dexter wouldn’t think he was inherently flawed, but he would have to learn about the most traumatic event of his life and Harry’s responsibility for it.If Harry lied, Dexter might think himself irredeemable, but he would still have his father as a positive role model, and he could still take pride in his ability to channel his urges, as Harry put it. That was a fairly easy choice for Harry, and he decided to spare Dexter the bloody details of how his Dark Passenger was born.

Deb Decided That Joining The Police Would Give Her Life More Meaning Than Playing Volleyball
Earlier inOriginal Sinseason 1, Deb got a call that Florida State University was still offering her a scholarship to play volleyball, even though she punched a teammate in the face and got kicked off the team. However, as she showed Harry, Deb decided to apply to Miami Metro’s police academy instead.Deb had a few reasons to choose the police over college, but the biggest was because she wanted to take control of her life. As she told the comatose Bobby Watt (Reno Wilson), Deb felt like her life was spiraling out of control and that she needed to make a change.
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That change became clear after she spoke to Tanya Martin (Sarah Michelle Gellar).Because Tanya told Deb that the best rush she got outside of sports was catching killers, Deb decided that being a police officer would give her life more meaning than playing volleyball would. She could make a real difference in real people’s lives as a cop, which she couldn’t do as a volleyball player. The Morgan family’s dynamics likely also influenced Deb, as she mentioned how Harry and Dexter would have to include her in their secret conversations from then on.

Why Brian Was Still Watching Dexter & The Morgans At The End Of Original Sin – Is He Really Going To Stay Away?
The final shot ofOriginal Sinseason 1 saw Brian Moser staring at Dexter, Deb, and Harry dancing together. Brian had, however, just agreed to stay away from Dexter, so it was a bit confusing why he was still stalking his little brother.Even though he knew Harry was Dexter’s best chance at happiness, Brian simply couldn’t stay away. He was still obsessed with his little brother, still mad at Harry, and still convinced the only way he could find happiness was by having Dexter back in his life. Even if it was just by watching from the shadows, Brian needed to be part of Dexter’s life.
What Happens To Dexter’s Biological Brother, Brian Moser
Brian Moser, Dexter’s brother, appeared in Dexter: Original Sin, but the prequel show didn’t explain just how important Brian is to the Morgan family.
Unfortunately, Brian wouldn’t be satisfied with watching Dexter from a distance. As fans of the originalDexterare aware, Brian would try to make contact with Dexter again years later in the sickest way possible.InDexterseason 1, Brian revealed himself as the Ice Truck Killer and began toying with Dexter, trying to slowly introduce himself and the truth about Laura’s death.Harry’s eventual death inOriginal Sinwas likely a big reason Brian decided to contact Dexter, as there was no one left to keep him from his brother.

The Real Meaning Of Dexter: Original Sin Season 1’s Ending Explained
Dexter: Original Sin Is About How Family & Love is What Separates Dexter From Other Serial Killers
Though it deals with a very specific situation of a serial killer vigilante,Dexter: Original Sinseason 1 is about much more universal themes. Dexter himself espoused the main theme ofOriginal Sin: the power and importance of family. He mentioned that though he would never be normal, family was the only thing that could save him.Dexter was right, too: the Code of Harry kept Dexter from being a monster like Aaron Spencer or Brian Moser, and Debra’s love kept him compassionate and kind. With his adoptive family’s help, Dexter was able to keep his Dark Passenger in check.
That line was endlessly important to Original Sin’s main message: what really separates Dexter from monsters and other serial killers is the compassion and empathy he has for others.

Family isn’t the only valueOriginal Sinseason 1’s ending values, however. As Bobby Watt was wheeled out of the hospital, Dexter remarked that he decided to kill other killers not because some people deserved to die, but because some people deserved to live.That line was endlessly important toOriginal Sin’s main message: what really separates Dexter from monsters and other serial killers is the compassion and empathy he has for others. Dexter doesn’t choose killers to cover his tracks or as an excuse to let his Dark Passenger feed, he kills them to protect their future victims.
Every Death In Dexter: Original Sin Season 1
There have been many deaths in the first half of the Dexter prequel series Dexter: Original Sin, including victims, killers, and a few key characters.
In many ways,Dexter: Original Sinis also a story about human nature, and how to figure out how to be a good person. Dexter constantly talks about how he was born to be a monster, and how his Dark Passenger can’t be contained, yet he also constantly contains it. He listens to Harry’s advice, he helps Deb when she needs him, and - perhaps most importantly - he chooses to save Nicky instead of killing Spencer.Dexter: Original Sinseason 1 is basically proof that no matter what, a person can always choose to do the right thing, even if they believe they’re a monster.