Warning! This article contains SPOILERS for Dexter: Original Sin episode 4 and Dexter season 1.Dexter: Original Sinhas provided a lot more context about Harry Morgan’s (Christian Slater) decision to adopt Dexter after Laura Moser’s (Brittany Allen) death, but it hasn’t explained why he didn’t adopt Brian Moser as well. As a prequel, thetimeline ofOriginal Sinand Harry’s flashbacks overlaps with some of Dexter’s backstory in the original show. That meansOriginal Singets to dive deeper into Dexter’s origins as a serial killer and his early childhood when Laura was still alive. While the show has answered many questions about Dexter, it also raised a few new ones.
Fans of the originalDexteralready know that Laura Moser was killed byHector Estrada, a drug kingpin, and that Dexter and Brian were locked in a shipping container filled with her corpse and blood for days. That traumatic experience is usually cited as the birth of Dexter’s “dark passenger” and his desire to kill. Harry eventually found both the boys in that shipping container, yet he only decided to adopt Dexter, not Brian.Dexterdidn’t devote much time to explaining Harry’s decision, however, andOriginal Sinhas only started to provide a reason why he didn’t adopt both of Laura’s sons.

Harry Thought Brian Was Already Too Traumatized For Him To Save
Harry Believed Dexter Could Block Out Laura’s Murder & That Brian Was Too Old To Forget
The main reason Harry didn’t adopt Brian is that he thought Brian would never recover from Laura’s death. Dexter was only a toddler when he was trapped in the shipping container with Laura’s body, but Brian was a few years older.Harry thought that Dexter would be able to repress the memory of her death, but that Brian was too old to do so. So, instead of adopting him and trying to raise him as a normal child, Harry thought it was best to have Brian put into a mental hospital so that they could attempt to treat the psychological damage from Laura’s murder.
So, instead of adopting him and trying to raise him as a normal child, Harry thought it was best to have Brian put into a mental hospital so that they could attempt to treat the psychological damage from Laura’s murder.

Original Sinhas also added a bit more nuance to Harry’s decision not to adopt Brian. AsOriginal Sinseason 1, episode 4proved, Brian was already exhibiting psychopathic tendencies like pulling the tails off lizards when Laura was still alive.It’s possible that Harry thought Brian was already a psychopath, and that Laura’s death would only make him worse, and had Brian institutionalized so that he couldn’t be a bad influence on Dexter. In any case, Brian’s existing bad behavior likely made it easier for Harry to believe he was too far gone to live a normal 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.
Harry’s decision to adopt Dexter and hospitalize Brian was also likely influenced by his own past. AsOriginal Sinepisode 1 showed, Harry had ason named Junior Morganwho drowned while he was watching him.Junior was about the same age when he died as Dexter was when Harry recruited Laura as a criminal informant, so Harry may have viewed Dexter as a replacement for his late biological son. If that was the case, Harry may have had Brian hospitalized because he didn’t resemble Junior enough.

Was Harry Wrong To Only Adopt Dexter After Laura Moser’s Death?
Brian Was Likely Always Going To Become A Killer, But Harry Could Have Helped Him The Same Way He Helped Dexter
Harry’s decision to adopt only one of the brothers is controversial, and it’s not clear whether he made the right choice. On the one hand, Brian was already showing the early signs of becoming a murderer through his torture of animals. Laura’s death only made those early warning signs worse, and he would eventually grow up to become the Ice Truck Killer.In that way, Harry was right about Brian, and he probably made the right call to not bring a psychopathic child into his home. Harry had Dexter, Doris, and, shortly after, Debra, to worry about, and Brian’s violent tendencies would have threatened them all.
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“And in the Beginning…”
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“Kid in a Candy Store”
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“F is for F***-Up”
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“The Joy of Killing”
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“Business and Pleasure”
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On the other hand, it’s possible that Harry’s decision not to adopt Brian is what sealed his fate. Growing up in a mental hospital couldn’t have been easy for Brian, and he clearly resented it long into adulthood. InDexterseason 1, Brian said as much to Dexter:
“You were three, a little bird with a broken wing. [Harry] wanted to make you all better. But me, I could see it in his eyes. All they saw was a fucked up kid. They all did, so they locked me up.”
There’s no way to tell for certain, but growing up in the loving household that Harry and Doris could have provided may have been enough to keep Brian from becoming a murderer. At the very least, he could have implementedthe Code of Harryfor both Dexter and Brian, and he could have kept Brian from killing over a dozen prostitutes. The idea of nature versus nurture has always been central toDexter, and Brian was arguably an even better example of it than Dexter himself. No one knows who Brian Moser would have been if Harry Morgan had adopted him inDexter: Original Sin.
Dexter: Original Sin
Cast
Dexter: Original Sin explores Dexter Morgan’s early years in 1991 Miami as he transitions from student to avenging serial killer. Guided by his father, Harry, Dexter crafts a moral code and navigates a forensics internship at Miami Metro Police, all while controlling his darker impulses.
Dexter
Dexter is a television series following Dexter Morgan, a blood spatter analyst for Miami Metro Police who secretly leads a dual life as a vigilante serial killer. Released in 2006, the show focuses on Dexter’s internal conflict as he hunts down criminals who elude justice within the legal system.