WARNING: SPOILERS ahead for Dexter: Original Sin episode 9.
Dexter: Original Sinepisode 9 reveals several unknown details about Brian Moser and one of his earliest encounters with his future girlfriend, Debra Morgan.Brian, better known as the Ice Truck KillerfromDexterseason 1, has become an unexpected antagonist in the prequel series. The penultimate episode ofDexter: Original Sinseason 1 peeled back some of the layers of Brain Moser’s troubling childhood after Harry and Doris Morgan chose to disown him after a series of violent outbursts.
Thechildhood relationship between Dexter and Brianprovides additional context to both of their origin stories. While Dexter mostly blocked out the horrific death of his mother, Laura, the older Brian could never unsee what Hector Estrada had done to his mom with a chainsaw.Harry and Doris decide to turn Brian over to his social worker, Barb, separating him from Dexter for years. If Brian had never tried to suffocate baby Deb inDexter: Original Sinepisode 9, his and Dexter’s lives may have turned out very differently.
Young Brian Trying To Kill Baby Deb Foreshadows Him Attempting To Murder Her In Dexter’s Season 1 Finale
Brian Tries To Permanently Silence Deb For Crying Too Loudly
Brian shockingly tries to suffocate baby Deb with a pillow during a flashback scene inDexter: Original Sinepisode 9. When a terrified Doris asks Brian why he tried to kill Deb, he eerily responds that she was too noisy. This was the final straw for Harry and Doris after Brian’s series of violent outbursts, which included punching through a glass door and striking Harry in the face. Young Dexter watches on, unaffected and quiet, unaware that decades laterhis big brother will try to kill his adoptive sister Deb inDexterseason 1.
In the season 1 finale of the originalDextershow,Brian also tries to kill Deb and then tries to get Dexterto be the one to do it. Dexter ultimately couldn’t go through with it and chose to save Deb instead of joining forces with Brian. Still, it was difficult to watch Dexter almost accept killing Deb in season 1, especially knowing how important she would become to him throughout the original series.
Why Dexter Chose To Save Deb Over Brian In Dexter’s Season 1 Finale
Helping Brian Kill Deb Would Have Broken Harry’s Code
InDexter: Original SinandDexterseason 1,Brian desperately wants Dexter to accept himas his real family. In both cases, Dexter chose Harry and Deb’s side, distinguishing himself from the monster that Brian has become. The key difference between Dexter and Brian – other than their upbringing – is that, thanks to Harry’s Code, he doesn’t kill innocent people. Dexter couldn’t empathize with Brian’s twisted desire to reunite their family by killing his “fake” sister, Deb.
Killing Deb would have broken Harry’s Code and led Dexter astray, turning him into the same unfortunate monster Brian became.
Thanks to Harry’s Code, Dexter has found purpose in controlling his Dark Passenger, a gift that Laura and even Brian could not have offered. Killing Deb would have broken Harry’s Code and led Dexter astray, turning him into the same unfortunate monster Brian became. In this way,Harry’s legacy and influence on Dexter saved Debin theDexterseason 1 finale.
TheDexter: Original Sinseason 1 finale releases on Friday, August 13, 2025, on Paramount+.
Brian may have been Dexter’s flesh and blood but he was also a major threat to Harry’s Code and Dexter’s sense of integrity in his “profession” as a vigilante serial killer.Dexter: Original Sinhighlights these key differences between Dexter and his brother.
