The first two seasons of “Dexter” benefited from a gripping cat-and-mouse scenario pitting its vigilante antihero against well-matched adversaries — first another serial killer, and then two dogged detectives. No such foe emerges in the initial episodes of the third cycle, but the show does delve deeper into the title character’s sweet but strange personal life, while introducing Jimmy Smits as an assistant district attorney with ties to a key investigation. Even taking a step backward, the show remains Showtime’s best, due in no small part to Emmy nominee Michael C. Hall.
Continuing to blend dark humor with its crime motif, Hall continues to evolve as Dexter Morgan, the Miami P.D. blood-splatter expert who — as trained by his adopted father — lives by a perverse “code” to feed his killing streak: Only exacting final justice against those who deserve it.
What makes Dexter interesting, however, is that despite his coldly homicidal tendencies, he’s not above the occasional slip-up. Here, that includes complications both with a murder that involves the brother of the ambitious Miguel Prado (Smits) and at home with Dexter’s fragile girlfriend Rita (Julie Benz), who gives Dexter a taste of normalcy that clearly makes him uncomfortable.
Smits and Hall play well off each other, but there’s an awkwardness to the way the relationship is structured that keeps the scenes — and for that matter, their entire story arc — from being completely satisfying. Part of it has to do with Dexter having to trust someone — something even approaching friendship — that doesn’t significantly advance the character, inasmuch as these questions retrace the groundwork laid in his interactions with Rita.
The producers also seem to be killing time, more than anything, with Dexter’s adopted and amusing foul-mouthed sister Debra (Jennifer Carpenter), whose frustrations with an unsolved murder and nosy internal affairs cop don’t seem to be going anywhere fast.
With the larger narrative diminished, what remains are the smaller moments. There Hall’s terrific performance — full of sly wit and contradictions — elevates the show, whether he’s enduring a yoga class, interacting with another sadist (as in the dentist) or bringing milk home to Rita and the kids after a rough night of administering vigilante justice.
Despite a streak of attention-getting concepts, few of Showtime’s series have managed to be this fully realized and consistently entertaining. After all, once you get beyond the premise it all comes down to execution, and that’s a task at which “Dexter” excels.