Dexter is really a show about solipsism. Dexter either controls his world or stands outside of it, above it. One of the show’s most common refrains is an image of him peering out from his lab at the other cops, all witlessly spinning about some misguided trail while he plots, ingeniously. His wry narration is ever present, affecting a post-slacker ennui, the sociopath’s sly wit. He constantly bemoans his lack of feelings, so routinely that it begins to sound specious, or at the very least unaware, which is a problem for a “smart” show so closely aligned with its protagonist’s narrative voice. We may recall John Lydon singing, “No feelings for anybody else,” with such feeling that we knew it couldn’t possibly be true. But Dexter cares only for himself, that’s for sure. The show in turn revolves in synchronous orbit. The viewer in turn loses interest.

Dexter Morgan is a serial killer. That’s the big hook, the conceit from which the show draws its darkly comic sensibility. Orphaned at a bloody crime scene, he was adopted by a detective who recognized his homicidal tendencies and worked with him to channel these urges in a (relatively) positive direction. To use his powers for good – find a target, establish guilt, murder and dispose. Since Dexter works as a blood splatter expert with Miami homicide – one of many implausible but narratively clever turns – he has access to all sorts of investigative tools for his kills. This provides a template for each episode, incorporating a weekly “kill target” in addition to the larger narrative arc. It’s all played comically and without any more believability than the plot would require, and the show is better for that distinction. Like a dark, premium cable satire of the Incredible Hulk. This is not reality, nor social commentary – this is Dexter.

The show doesn’t shy away from the moral ambiguities of its twisted protagonist, even if it does so on its own terms. In one episode, he accidentally slays an unexpected assailant during a kill attempt, which haunts him not for its immorality but for the breaching of his code. He’s a serial killer, a real one, who is constantly fighting to keep his urges at bay. This show treats serial killing with the same sort of reverence that Breaking Bad did blue crystal meth; its moral universe is defined by that aberration, so that the viewer can learn and respond to the rhythms of its strange logic. It’s clever, subversive writing. The idea that this show can find real emotion in scenes with Dexter commiserating with a rival serial killer is one of its most audacious turns. Quirky as it is though, Dexter is not as immersively great as Breaking Bad. It doesn’t grow and doesn’t get sharper, so it just gets dull.

Season One is based around Dexter’s investigation of the Ice Truck Killer, setting the pattern for each season’s rival serial killer plot. His step sister Deb – tenacious, pretty, purveyor of profanity – also works with Miami homicide. Her own investigations invariably coincide with Dexter’s extracurricular activities, which leads to all sorts of suspenseful paths. The twist at the midpoint of this season is actually pretty shocking; perhaps there were viewers keen enough to spot it before the revelation, but I found it to be a chilling surprise. The second half of the season gets even more bizarre, delving deeper into Dexter’s past with some convoluted twists that soon become the show’s trademark. A tightly written season that unfolds methodically, with a disciplined sense of narrative.

Season Two plays on these elements with the unfortunate discovery of Dexter’s “waste management” methods. The underwater view of a field of black trash bags on the ocean floor is so chilling that we don’t need the scare shot of one being ripped to reveal a severed arm. We already knew what was in there. Dexter doesn’t express much concern other than vexation at his work being credited to “The Bay Harbor Butcher.” And why should he worry? No one, except for one rogue detective, suspects him. Still, this is a scenario in which we can welcome the show’s implausibility, its pulpy dark comedy; a true crime reading would probably be too gruesome to endure. Twists and turns abound, usually at the end of an episode – an old trick that starts to wear thin and nearly causes the whole narrative to collapse on itself with the season’s conclusion.

Season Three is just bad – it doesn’t work at all. TV star Jimmy Smits joins the cast as a prosecutor who recognizes in Dexter an opportunity to “finish off” those defendants who got away. An intriguing premise that could have led to some interesting extralegal entanglements. Unfortunately, it’s handled clumsily: Smits plays the character with dense gullibility, following Dexter around like a sycophant, when it seems the role might have called for cold calculation. By the time he’s wandering around with Dexter in dark sunglasses to join him on kills, my own interest in this season had long since been wrapped up in plastic. Skip this one entirely.

Season Four‘s casting choice is genius: John Lithgow is perfect as the family man slash serial killer, creepy and clerical, a sociopath who sings with the church choir. An outstanding performance. This season really feels like the show’s subversive peak, with Dexter’s personal and professional concerns converging with his murderous hobby, along with some cleverly played interactions with Lithgow. But it’s also a breaking point – consider sister Deb, who is portrayed as a tenacious detective, with sharp instincts, who still can’t seem to discern the fact that her brother is a prodigiously active serial killer. There’s that solipsistic problem again, as these other characters must bungle their way through their own casework so that we can continue to follow Dexter’s narrative. The same tricks of suspense are used every season, nearly every episode, until they are no longer effective.

I had to tap out midway through Season Six. It’s not that the show devolves so much as it remains too static, stuck in its own formulas. Even new narrative wrinkles – which I won’t spoil for more patient viewers – feel ineffective against the deathly rigid formula of each episode. Dexter’s world will never change, though he will continue to pontificate about it through his flat narration. Once we recognize the limits of his insight, our interest wanes. At a certain point, he only appears to be smart because those around him are so dumb. Breaking Bad was constantly testing its limits, widening its scope. Dexter remains locked in its protagonist’s wry narration. I actually don’t think that the quality of show declines so much as my own patience with its pulpy formula. At its best, it’s smart, suspenseful television, provocative and charmingly self aware. Watch the first two seasons and the Lithgow one and leave it there; otherwise be prepared for the realization that the weekly travails of a smart, affable serial killer are actually kind of predictable and dull.