Forensics expert Dexter Morgan (Michael C. Hall) continues to moonlight as a serial killer in the third season of Dexter. (Astral Media/TMN) Dexter Morgan, the central figure of Showtime’s breakout drama Dexter, is not your run-of-the-mill serial killer. Neither a CSI-variety ghoul nor a 48 Hours-style creep, Dexter (Michael C. Hall) is, by his own description, a “unique monster” — one more closely related to the charismatic anti-heroes of comic-book lore than any villain Bill Kurtis would devote an hour to profiling.

A blood spatter expert for the Miami police department by day, Dexter is possessed of a secret power: the ability to recognize other killers on sight. But more than that, Dexter has standards, a strict killing code. He only kills those who “deserve it,” ridding the world of sadistic predators by sadistically preying on them. Yes, Dexter’s a complicated guy, and his identity crisis is what has made the show such compelling viewing. Seasons one and two have seen Dexter struggle with his complicated status in the pantheon of TV heroes. Season three, which begins Sept. 28, hints that our killer is about to come into his own just as he encounters another nemesis, assistant district attorney Miguel Prado (played by Jimmy Smits).

Fascination with serial killers isn’t new. Manhunter, Silence of the Lambs, Copycat, Natural Born Killers, In the Cut, Seven, the truly wretched Saw films — all make hay out of the grisly handiwork of murderers. But these killers are less people than types: the creepy white guy/sex pervert (Manhunter,Copycat,In the Cut), evil geniuses (Seven,Saw), Bonnie and Clyde-like cartoons (Natural Born Killers) and yes, even esthete cannibals (Silence of the Lambs). Character, and by extension audience sympathy, is usually reserved for cops or investigators, rarely the perpetrator. (As for the ill-starred victims, they’re just ghoulish props, hapless extras serving the plot.)

TV dramas have shown more interest in what makes bad guys tick. Though Sopranos fans may cry foul, the HBO prison drama Oz — which ran for four glorious seasons and two not-so-hot ones — possessed the most morally problematic cast ever. Comprised solely of the residents of Oswald State Correctional Facility, the characters included murderers, white supremacists, mothers who’d killed their children, rapists, unrepentant sadists, etc. Although you’d want to avoid them in real life, Oz creator/writer Tom Fontana wrote about them for TV and somehow made you care about each one.

Dexter isn’t about violence — the camera wisely pulls away when the going gets too rough. It’s about character. Inspired by Jeff Lindsay’s 2004 novel, Darkly Dreaming Dexter, the show brings curiosity and potential moral value. Is Dexter a killer or a hero, good or evil? These are the questions from which the show derives its energy, and they charge every scene.

Dexter (Michael C. Hall) dates Rita (Julie Benz) in order to appear normal. (Astral Media/TMN)Season one put these forces into play immediately — Dexter’s first victim was a child molester, a universally loathed figure. Though anxious to get down to business, Dexter took the time to point out that unlike the child molester, he’s not ruled by compulsion — he’s governed by “standards.” Dexter kills killers, but is fundamentally incapable of harming the innocent (“I could never, ever kill kids,” he confides).

Dexter’s “code” comes courtesy of his adoptive father, Officer Harry Morgan (James Remar). The sympathetic cop took note of young Dex’s destructive instincts and flat affect and advised him to conceal his sinister leanings — to act normal — and direct his malevolence toward the wicked in secret. Harry never told Dexter the reason he was the way he was; instead, Harry gave him a program for coping. That program manages to be a mixture of self-interest and altruism. “Don’t get caught” is the first rule of the code; “Protect the innocent” is the second.

Dexter feels dead inside, and he compensates for his blank interior by acting zealously normal. He bowls, snags a girlfriend (Julie Benz) and is a good if emotionally clueless brother to his adopted sister, Deb (played by the remarkable Jennifer Carpenter). But Dexter’s assumption of the role of Regular Guy sits uncomfortably on his broad shoulders. His golf shirt is as tight as his smile. Michael C. Hall, who played David Fisher on HBO’s Six Feet Under for five seasons, gathers a lot of cloud in a simple flex of those woolly eyebrows. Dexter’s humour — dark, with a deadpan delivery — is a saving grace. (Indeed, audiences will forgive many sins if you can make them laugh right before you stuff the bodies of two human traffickers into trash bags.)

Dexter’s code establishes his reason for killing, but the origin of this urge was the real narrative interest of season one. The answer went a long way toward explaining Dexter’s emotional numbness and his fascination with blood and vengeance. Illumination came via a Miami-based serial murderer named Rudy Cooper (Christian Camargo), or the Ice Truck Killer, who took a special interest in awakening Dex’s repressed childhood memories. As a toddler, Dexter witnessed the chainsaw killing of his mother. The Ice Truck Killer knows what happened because he was there, too — he’s really Dexter’s long-lost older brother, Brian.

In the third season, Dexter joins forces with assistant DA Miguel Prado (Jimmy Smits) to pursue a murderer who affects both of their lives. (Astral Media/TMN)Rudy kills for sport and manipulates the innocent — including Dexter’s sister — for pleasure. Unlike his big bad brother, Dexter allies himself with the victims of crime. A superhero in plain clothes, Dexter springs to action when justice fails to punish the evildoer. Part of his killing ritual is showing the doomed killers photographs of their victims before exacting brutal reparation. Rudy’s childhood trauma may explain his compulsion, but we don’t feel his pain because he’s without a single redeeming human feature.

In season two, Dexter was in the throes of a full-on identity crisis. Confused, he dabbled with rehabilitation, attending Narcotics Anonymous meetings for his “addiction” to blood. In a neat bit of parallelism, Dex’s personality crisis coincided with the public manhunt for the Bay Harbor Butcher.

In keeping with the show’s two-steps-forward, two-steps-back approach to moral development, the Dexter of season two was a more complex animal. The more he uncovered about the circumstances of his mother’s death — and Harry’s involvement — the more he began to question the integrity of the code he was given. By the climax of season two — and it was a doozy — Dex concluded that questions of good and evil are hard to answer, perhaps even impossible.

The “code,” however, remains a necessary evil. It’s a practical means of survival (Don’t get caught) and keeps him in touch with his better human nature (Protect the innocent). Without the former, the show is just creepy, while the latter keeps Dexter on the right side of the audience’s sympathy.

Season three of Dexter begins on The Movie Network and Movie Central on Sept. 28.

Flannery Dean is a writer based in Toronto.