This post contains spoilers for "Dexter" and "Dexter: New Blood."

"Tonight is the night." And it will happen again and again. It has to happen." These opening lines grace the pilot episode of Dexter in which blood spatter specialist Dexter Morgan (Michael C. Hall) drives around while on a prank. What sets this show apart from most police procedurals is its first positioning of Dexter as a morally complex figure, a killer who (mostly) kills other killers who have managed to escape the justice system. However, this moral positioning begins to unravel once his meticulous plans begin to spiral out of control and threaten the false identity he has painstakingly crafted over the years. This tension between our intimate knowledge of Dexter's twisted vigilantism and the growing suspicion of his crimes gives Dexter the edge it needs to become a tense, exciting, character-driven procedural.

That said, even the best shows lose their wayand "Dexter" has been making some questionable storytelling choices in recent seasons. To remedy that, Dexter: New Blood served up a treat for longtime fans, where the story picks up 10 years after the finale of the original series, in which Dexter (apparently) faked his death. "New Blood" marks a fresh start for Dexter, who seems to have suppressed his murderous instincts in favor of a mundane existence away from crime scenes. However, the "Dark Traveler" (the conceptual personification of his trauma) in him is sure to awaken after being forced to face the past, and "New Blood" proves that old habits and impulses die hard.

This should come as no surprise, but Dexter killed people. A lot of people. He is a serial killer with an elaborate modus operandi designed to avoid detection, and even some of his more spontaneous killings inform the established worldview. How many people has Dexter killed? The answer is a whopping 149.

Personal definitions of justice can quickly become a slippery slope once motives and egos run rampant. It's not surprising to compare Dexter's (self-accepted) moral superiority to that of Death Note's Light Yagami, who honestly comes to believe that killing criminals who evade the system is morally justified. Light's criteria for using the Death Note may be more arbitrary and selfish than Dexter's trauma-fueled quest to become a serial killer's vigilante, but both suffer from the same warped, inflated morality that conveniently sidesteps self-examination. While Light's intentions spiral into megalomania and obsession with playing god, Dexter's interpretation of Harry's Code becomes increasingly out of control once his moral compass (or lack thereof) is challenged.

Not every person among the 149 people Dexter killed was part of his killing ritual, in which he reimagines the murders as an offering to the innocent victims, whose memories and personal belongings are transformed into objects of veneration. There are murders outside of Harry's Code where he targets people who have never killed anyone before, such as killing Oscar Prado in self-defense and committing a mercy killing on Camilla Figg. There were times when Dexter killed an innocent by mistake, like Jonathan Farrow, whose sidekick Timothy turned out to be the real killer.

Dexter's need to kill is an impulse caused by childhood trauma, and the Codex is a way to channel these desires with the fewest casualties. However, it is impossible to derive personal justice from personal revenge, as the two often go hand in hand: this has led to some personally motivated murders throughout the series. Examples include his brother Brian Moser, who spent years killing sex workers, and Arthur Mitchell/The Trinity Killer, whose methods he admired for years.

At the end of Dexter: New Blood, Dexter realizes that his Code is flawed and that a vigilante killer should be judged by the same standards that apply to the killers he killed. In case you want more of Dexter, check out the prequel series Dexter: Original Sin, which premiered on December 13, 2024, on Paramount+ with Showtime.