10 Biggest Timeline Inconsistencies & Plot Holes In Dexter: Original Sin

The Dexter prequel show Dexter: Original Sin has already changed quite a bit from Dexter Morgan's (Patrick Gibson) early life and the timeline of his story. Original Sin has clearly done its homework on the main Dexter series and its accompanying sequel series, Dexter: New Blood. There have been several great Easter eggs and references in the prequel series, from Original Sin's Trinity Killer reference to the possible Brian Moser sightings throughout the show. It hasn't been completely faithful to the other shows, however, and Original Sin's timeline has made some major changes to the established Dexter canon.

A certain number of small retcons and timeline inconsistencies were basically unavoidable for Original Sin. The main Dexter series explored Dexter's youth and early days as a serial killer to a surprising extent. Original Sin would have had a nightmare of a time carving a completely novel story out of all the small reveals scattered throughout Dexter's eight seasons. While some creative liberty was to be expected, Original Sin has still made some fairly major changes to Dexter's timeline, and it's created a few glaring plot holes for the original series and New Blood. These 10 inconsistencies are the biggest in the prequel show.

10 Dexter Should Still Be In College During Original Sin

Dexter's Earliest Kills Happened While He Was In College & His 20-Year High School Reunion Was In 2011

The main problem Original Sin presents to the timeline Dexter established is that it's set too early. Original Sin follows Dexter just after he graduates from college in 1991, but the premiere of Dexter season 6 saw Dexter attend his 20-year high school reunion in 2011. Dexter should have graduated from high school, not college, in 1991, yet Original Sin both tweaked Dexter's age and rushed him through college in order to graduate at age 20. It's perhaps not the most important change, but it is fairly significant given how prominent Dexter's high school reunion was in Dexter season 6.

If it had stuck to the original show's timeline, Dexter would have been hunting down drug dealers and co-ed murderers instead of loan sharks and serial killers.

The main way Dexter's age changes things for Original Sin is through his victims. Dexter alluded to the idea that Dexter was killing people all throughout his college career, yet Original Sin established that he only took his first victim a week before he graduated. The forgotten webseries Dexter: Early Cuts even established that Dexter killed one of his college professors and one of his classmates. If it had stuck to the original show's timeline, Dexter would have been hunting down drug dealers and co-ed murderers instead of loan sharks and serial killers.

9 Debra Morgan Should Be A Lot Younger Than Dexter In Original Sin

Dexter Made Debra Seem Much Younger Than Original Sin Made Her

Dexter wasn't the only member of the Morgan family whose age was changed in Original Sin. Debra Morgan's (Molly Brown) age actually changed even more than Dexter's did. In Dexter season 1, Deb was presented as a rookie cop making her way up through vice and into homicide, while Dexter was 35 years old and an established figure at Miami Metro. Dexter season 8 even confirmed that Deb was born eight years after Dexter, yet Original Sin is presenting her as just four years younger; Dexter is 20 and Deb is 17. With that age gap, Debra would have been 31 when she first got transferred to homicide.

None of Dexter: Original Sin's retcons, timeline inconsistencies, or plot holes necessarily make it a bad prequel.

The difference in Dexter and Deb's age gap also changes their sibling dynamic significantly. In the original show, Dexter seemed to have taken care of Debra to an extent, especially after Harry's death. In Original Sin, however, Debra seems to be much more independent, and she even takes care of Dexter in some ways. Deb's responsible for making dinner, she babysat him after he accidentally got high, and she's even encouraging him to be more social. Deb in Original Sin is almost unrecognizable from the shy and self-conscious Deb who had to ask her big brother for help several times in Dexter season 1.

8 Original Sin Changed Dexter's Third Kill

Dexter's Third Kill Was Originally A Drug Dealer, Not Levi Reed

Dexter's first six kills were revealed in some of Dexter's flashbacks and Early Cuts' episodes, yet Original Sin changed them as well. One in particular, Dexter's third kill, was especially different in the prequel show. In Dexter season 8, Harry Morgan (James Remar) revealed that Dexter's third kill was an unidentified drug dealer, but he also mentioned that it was the first time Dexter displayed photos of his victims. Original Sin, however, made Dexter's third kill Levi Reed (Jeff Daniel Phillips), a child murderer who did not deal drugs. Harry also revealed that in a confidential meeting with psychiatrist Evelyn Vogel, so he had no reason to lie.

There's no way to reconcile Original Sin and Dexter on this particular issue: it's an outright contradiction of something the latter established very explicitly. Switching from an unnamed drug dealer to Levi Reed both made Original Sin more original and let it dive deeper into Harry's decision to use Dexter as a weapon for justice, but it changed the main series to do so. It was probably for the best, as Levi Reed's death was a great moment in Original Sin, but even a good retcon is still a retcon.

7 Original Sin Completely Ignored Dr. Vogel From Dexter Season 8

Harry Morgan Was Supposed To Go To Dr. Vogel For Advice About Dexter's Early Kills

Original Sin didn't limit its retcons of Dexter season 8 to his victims, however. Dr. Evelyn Vogel (Charlotte Rampling) has also been written out of Dexter's early life as a serial killer entirely. Dexter season 8 revealed that Vogel helped Harry come up with the Code of Harry, and that the two met frequently as Dexter started killing people. They made tapes shortly after several of Dexter's earliest kills, like after he killed his third victim. Original Sin should include scenes of Harry discussing Dexter's kills with Vogel, but it has yet to even introduce her to the show.

Other than Harry himself, Dr. Vogel had the biggest impact on Dexter's early life and development out of anybody in the Dexter franchise. It was because of Vogel's advice that Harry kept training Dexter as a serial killer, even despite his reservations. By removing Dr. Vogel, Original Sin is putting more of the responsibility for Dexter's violence on Harry, and making him even more guilty for using Dexter as a tool for murder by proxy. Without Vogel, Harry will also have no one else to turn to when he discovers just how heinous Dexter's killing method is, which will make his eventual suicide even easier to believe.

6 Harry Morgan Slept With Other CIs Besides Laura Moser

Original Sin Makes Laura & Harry's Relationship Seem Like A Momentary Lapse Of Judgement

Original Sin has done quite a bit to make Laura Moser's (Brittany Allen) story more fleshed out, but it had to change Dexter to do so. In Dexter season 2, Deb learned that Harry had a long list of criminal informants that he slept with, and one of them even suggested Harry picked his CIs specifically because he wanted to have a sexual relationship with them. Original Sin seems to have changed that, however, as Harry's relationship with Laura is being portrayed as an unintentional bout of passion and weakness, rather than part of a larger pattern of adultery.

Making Harry and Laura into star-crossed lovers helped Original Sin quite a bit. Laura feels much more fleshed out, and the show's flashbacks have added even more moral grayness to Harry as he continues to force the woman who loves him to conduct dangerous work as a criminal informant. It also, however, detracts from the moral grayness the original show gave Harry by revealing he was a serial cheater and womanizer. It also somewhat excuses Harry's affair by showing that his romp with Laura was a response to his marital problems with Doris (Jasper Lewis).

5 Harry Morgan Had A Different Partner During Original Sin

Harry's Original Partner Was Davey Sanchez, Not Bobby Watt

One of the more blatant changes Original Sin has made to Dexter's lore concerns Harry's partner. In Original Sin, Harry has been working with Bobby Watt (Reno Wilson) since the 1970s. However, in the original Dexter, Harry's partner was named Davey Sanchez. Despite not appearing on-screen, he was actually a very important character. Davey was murdered by a man named Juan Ryness, and Harry walked in on Dexter taking revenge against Ryness. Seeing one of Dexter's mutilated corpses first hand was one of the main reasons Harry ended up taking his own life.

While Bobby Watt does directly contradict Dexter's description of Davey Sanchez, it's not actually as important of a retcon as other changes. Original Sin could still stay true to the most important part of Davey's story by eventually having Bobby killed, and having his murderer walk free. Thus, Harry would have Dexter kill the murderer, setting off a domino effect that causes Harry to commit suicide. At this point, Original Sin has effectively only changed the name of Harry's partner, and it could easily stay true to Dexter lore.

4 Captain Matthews Should Already Be At Miami Metro Homicide

Matthews & Harry Had A Longstanding Friendship, Yet Original Sin Hasn't Introduced Him Yet

Another of Original Sin's changes affects a different character from the main Dexter series. In Original Sin, Captain Aaron Spencer (Patrick Dempsey) is in charge of Miami Metro's homicide division, and it seems he's had the job for quite a long time. Spencer and Harry are good friends, and they have quite a history together. Harry also had a close relationship with a different police captain in Dexter, however; Captain Thomas Matthews (Geoff Pierson). In the early 1990s, it should be Matthews leading Miami Metro in Original Sin, not Spencer.

Dexter heavily implied that Harry and Matthews had a good and long-standing friendship with one another. One flashback saw Matthews visit the Morgan family household on Deb's birthday, and he was good enough friends with Harry to hide his official cause of death in his autopsy to protect Deb and Dexter. That type of friendship takes years to foster, but it currently looks like Harry and Matthews only knew each other for a short time in Original Sin. Even if Original Sin brings Matthews in to replace Spencer, there shouldn't be enough time before Harry's death for them to grow that close.

3 Dexter Shouldn't Be Working With Harry At Miami Metro In Original Sin

Harry Originally Died When Dexter Was Still In College, So They Shouldn't Have Experience Working Together

Perhaps one of the broadest timeline inconsistencies in Original Sin is the mere fact that Dexter and Harry are working together at all. In the original show, Harry died while Dexter was still in college, long before they could have been coworkers. Dexter even used that fact on several occasions, as both Dexter and Deb had to go to Captain Matthews to get information about Harry's time at Miami Metro. Now that Original Sin showed that Dexter worked side by side with his dad, however, he should have at least some firsthand knowledge of Harry's career, or at least a better friend to ask than Matthews.

Both Angel Batista (James Martinez) and Maria LaGuerta (Christina Milian) should have started their detective careers years after Harry died.

Dexter isn't the only character who shouldn't be working with Harry Morgan in Original Sin, though. Both Angel Batista (James Martinez) and Maria LaGuerta (Christina Milian) should have started their detective careers years after Harry died. Neither of them ever made reference to personally knowing and working with Harry, even though Maria was his partner on the NHI Killer case. Dexter also wondered how he had grown so close to Batista in Dexter season 1, even though Original Sin's new timeline means that they had been coworkers for 15 years and Dexter was the son of Batista's late friend.

2 Dexter: Original Sin Undid New Blood's M99/Ketamine Retcon

Dexter Used M99, New Blood Changed It To Ketamine, & Original Sin Changed It Back

One of Original Sin's most unusual retcons didn't actually change the original Dexter. In fact, the franchise reverted to the main series' canon after Dexter: New Blood changed it in 2021. New Blood infamously changed Dexter's drug of choice from the horse tranquilizer M99 to the common sedative ketamine. It was a controversial decision that many fans of New Blood saw as an overly convenient plot contrivance, but Original Sin switched back to the original drug. A large portion of Original Sin episode 5 was even dedicated to showing how Dexter got his hands on M99, not ketamine.

Though it reestablished the status quo of Dexter's go-to sedative, Original Sin's choice of M99 over ketamine made New Blood's decision to use the latter even more confusing. If Original Sin had doubled down on ketamine, then New Blood would have been a simple - albeit controversial - retcon. By changing back to M99, however, New Blood's use of ketamine is now completely unexplained. Angela (Julia Jones) seemingly found out Dexter was the Bay Harbor Butcher through sheer luck and some internet blogs that got key facts of the case wrong, as Original Sin proved that he never used ketamine at all.

1 Harry Morgan Told Dexter Why Taking Trophies Was A Bad Idea In Original Sin

Despite Harry's Advice About Trophies, Dexter Still Went On To Take Blood Slides

He hasn't started taking blood slides yet, but Dexter did take a trophy already in Original Sin. In a bit of foreshadowing to his eventual use of blood slides, Original Sin saw Dexter take Nurse Mary's earrings as a trophy from his first kill. That led to a slew of problems that eventually culminated in Harry explaining why trophies create a direct line of evidence back to Dexter and how it violates the first rule of the Code: don't get caught. Despite Harry giving him an explicit warning not to take trophies, Dexter would still go on to take blood slides by the time of the main series.

Episode #	Episode Title	Release Date & Time On Paramount+ With Showtime	Release Date & Time On Showtime
1	"And in the Beginning..."	December 13, 2024 @ 12:01 am ET	December 15, 2024 @ 10 pm ET
2	"Kid in a Candy Store"	December 20, 2024 @ 12:01 am ET	December 22, 2024 @ 10 pm ET
3	"Miami Vice"	December 20, 2024 @ 12:01 am ET	December 22, 2024 @ 11 pm ET
4	"Fender Bender"	December 27, 2024 @ 12:01 am ET	December 29, 2024 @ 10 pm ET
5	"F is for F***-Up"	January 3, 2025 @ 12:01 am ET	January 5, 2025 @ 10 pm ET
6	"The Joy of Killing"	January 10, 2025 @ 12:01 am ET	January 12, 2025 @ 10 pm ET
7	"The Big Bad Body Problem"	January 24, 2025 @ 12:01 am ET	January 26, 2025 @ 10 pm ET
8	"Business and Pleasure"	January 31, 2025 @ 12:01 am ET	February 2, 2025 @ 10 pm ET
9	"Blood Drive"	February 7, 2025 @ 12:01 am ET	February 9, 2025 @ 10 pm ET
10	"Code Blues"	February 14, 2025 @ 12:01 am ET	February 16, 2025 @ 10 pm ET

Throughout the original series, Dexter treated the Code of Harry like law. There were, of course, a few kills that violated the Code of Harry, but those were during moments where Dexter was either mistaken or going through an internal turmoil. Dexter's decision to take blood slides directly and willfully contradicted the Code of Harry, and the fact that Original Sin had Harry expressly warn Dexter about it makes it an even more egregious rule break. On its own, Harry's warning isn't much of a plot hole, but it adds up with Dexter: Original Sin's other inconsistencies.