Jeff Lindsay's "Darkly Dreaming Dexter" is a wisp of a debut novel, a thinly plotted little thriller with only one thing going for it, lead character Dexter Morgan. Our protagonist, Dexter is a blood splatter expert working with the Miami police department. Dexter's good at what he does, because when Dexter isn't solving murders, he's committing them, doing what he sees as his part to rid the city of the kind of scum the law can't touch.

Showtime has made a weekly series out of source material that would have been stretched for a two-hour feature, so it's a pleasure to note that the premium cable network's "Dexter" is a substantial improvement. It's stylish, sly and full of local color and it features a career-redefining performance by Michael C. Hall, who makes sure that Dexter is always compelling, but never excessively sympathetic.

Showtime's "Dexter" takes its basic spine from Lindsay's book. Dexter was trained by his cop stepfather (James Remar, making the creepy seem paternal) to use his twisted instincts for something that resembles justice. Dexter may be a bit of an unfeeling monster, but he's been well socialized, with a sexy police stepsister Debra (Jennifer Carpenter, looking glad to be far from "The Exorcism of Emily Rose"), differently stunted girlfriend Rita (Julie Benz) and a boss, Lt. LaGuerta (Lauren Velez) who also has the hots for him. His life is a carefully assembled facade that becomes more complicated when a new serial killer hits the town, dismembering bodies and showing a very personal interest in Dexter. Sounds twisted, but it's also quite funny.

The main plot involving Dexter's rival is unchanged from the book, but myriad supporting details have been added to beef up all of the supporting characters, particularly Erik King's Doakes, the only officer with the good sense not to trust Dexter. He's been given a subplot involving a Cuban drug kingpin that isn't fresh, but that helps fill the time. Also benefiting from extra depth are Debra and Rita, with Carpenter's coltish professional enthusiasm and uncertainty and Benz's utter vulnerability paired nicely with Dexter's still exterior.

Dexter isn't an easy guy to like and the show's gratingly introspective narration doesn't help. Taken largely from Lindsay's book, the voice-over reinforces the show's brand of day-glo noir (director Michael Cuesta paints Miami's colorful exteriors with a splashy gloss), but it also overarticulates the character's snarky contradictions. Hall does that well enough without speaking. Hall's Emmy nominated work in "Six Feet Under" was impressive, but I forgot about David Fisher in seconds. On the page, Dexter is so internalized that you can't imagine how he could operate in the real world, but Hall creates a character for whom the line between friendly and deranged might just be a trick of the light. His sardonic delivery provides laughs, but Hall carries himself with the confidence of a man who knows that the rules of society no longer apply to him.

The opening credit sequence of "Dexter" is Emmy-worthy pop art, intensely heightened close-ups of our heroes morning routine meant to accentuate the utter brutality of the most banal of activities. Shaving, squeezing juice and putting on a t-shirt are imbued with a menace that perfectly underlies the show's theme, which suggest that Dexter's matter-of-fact desensitization to killing is just a symptom of a contemporary society where our collective senses have been numbed.