Heroes need their villains but not nearly as badly as anti-heroes do. The second season of Showtime's dark comedy Dexter, which follows the comings-and-goings of a forensic analyst who triples as serial killer and family man, floundered due to a noticeable lack of a real nemesis for its title character to tango with. They offered a few adversaries: Keith Carradine's suave FBI agent, Erik King's suspicious Sgt. Doakes, and Jaime Murray's seductive NA sponsor. None of these characters matched the protagonist's wits, however, and it left both Hall's hilariously congenial sociopath and the show in lukewarm territory.

The third season reimburses its fans for season two by giving Dexter a protégé, a best friend, and a nemesis. The kicker is that they're all the same person. Botched by a frantic drug dealer, Dexter kills someone without his regular procedure and is left, once again, questioning the "killer code" handed down to him from his stepfather Harry (James Remar). That someone happens to be the youngest brother of Assistant District Attorney Miguel Prado (Jimmy Smits in fine, feisty form). Dexter hangs the death on a soulless junkie who he butchers in his usual fashion. When Prado walks in on Dexter, looking for his own revenge, he is surprisingly accepting of, even excited by, Dexter's work.

Working the thin line between cop and criminal with notable invigoration, the show revs its chainsaw even louder when Miguel asks Dexter to teach him his methods. In a daze from his first "real" friendship and the news that his girlfriend (Julie Benz) is pregnant, Dexter agrees and, in one of the season's strongest episodes, allows Miguel to kill a gambler who pays off his debts by whacking people. At the same time, Dexter's sister Deb (Jennifer Carpenter) is hunting down a serial killer named the Skinner and falls for her guitar-playing CI (David Ramsey).

Things go south when Prado strikes out on his own to kill a rival attorney (Anne Ramsay) and begins to break Dexter's code. The show comes, as usual, to a sanguinary finale but, unlike its past two seasons, the overall focus is tighter and more dedicated to Dexter's oddly communal world. The show bets the house on the chemistry and tension between Hall and Smits. It's languid, at first, but builds from its early rumblings into a devastating crescendo with Dexter realizing that he'll never feel the full embrace of the ordinary. David Zayas, C.S. Lee, and Lauren Vélez continue to fill out Dexter's precinct with smart, well-detailed performances while Desmond Harrington, as Deb's new partner, offers some welcome mystery.

Dexter is, like Weeds, highly entertaining television that seduces us into believing its central premise which, in both cases, skirts absurdity. As it so often does, much of its tone and mood is dependent on the crucial decision of what to explain and what not to explain; questions are left unanswered but none that the viewer outwardly cares about. We believe, like his friends and family, that Dexter -- likable homicidal maniac or vigilante -- is a good man and a good father figure. Like most good television, we believe the lie because the people telling it are, above everything else, good salesmen.