There’s not much to “Hap and Leonard,” but that’s not necessarily a bad thing when it comes to light, caper-driven stories. The trouble with the new Sundance drama is that its charms are meant to arise from the complicated relationships among a central trio of characters, but they never manage to make much of an impression, individually or in various combination.

Tonally, “Hap and Leonard” appears to be aiming for the sweet spot that FX’s “Justified” hit for most of its run. Like that show, this one is adapted from a series of novels that depict the shaggy adventures of wayward men with a penchant for booze and the wrong bed partners.

But unlike the atmosphere of “Justified,” which built on a strong foundation supplied by novelist Elmore Leonard, that of “Hap and Leonard,” which is based on books by Joe R. Lansdale, never quite coalesces into something truly diverting. This show should be a swampy, escapist saga with poignant overtones, but that version of the tale can only occasionally be glimpsed amid the overwritten dialogue and the stilted pacing. For the most part, there’s not much of a spark here.

It’s a shame, given the cast. James Purefoy brings a charming raggedness to the role of Hap, though, as is the case with many U.K. actors, his Southern accent tends to wander all over the place, from Maine to Marfa, Texas. As Leonard, Michael Kenneth Williams gives a finely textured performance, and his charisma keeps more than a few scenes afloat.

The third member of the trio is Christina Hendricks; she plays Hap’s ex-wife, Trudy, who brings Hap and Leonard a scheme they all are hoping will make them rich. As she did on “Mad Men,” Hendricks does a fine job of quietly showing how much the men around her character disappoint her, and how difficult it has been to keep any kind of optimism in her hard-scrabble life.

Chemistry and pacing problems afflict the series from the start, nor is the backwoods setting distinctively rendered (the series was filmed in Louisiana, standing in for Texas). Purefoy and Williams are fine actors but never really click as a duo, and as soon as the three leads arrive at the sketchy compound of Trudy’s hippie-like new boyfriend, things grind to a halt regularly. The characters at the compound not only don’t add anything to the proceedings, they’re so predictable and thinly drawn as to detract from the rest of the series.

Like any show aspiring to noir greatness, “Justified” had terrific dialogue, and that’s where “Hap and Leonard” falls shortest. The writing for the key characters is often quite mannered and belabored when it’s not ponderous (An example: “You’ve got nothing left inside to hold the dark away”). There are some attempts to sketch out an argument between idealism and greed among the characters, but like the rest of this meandering, six-episode “event series,” the theme never quite comes into meaningful focus.

It’s as if “Hap and Leonard,” which is set in the 1980s, is suspended in time and geography between the fine first season of “True Detective” and the overwrought second season of that HBO drama. This Sundance show’s literary ambitions are clear, but the execution is only occasionally effective.

TV Review: ‘Hap and Leonard’

(Series; Sundance TV, Weds., Mar. 2, 10 p.m.)

  • Production: <hr /> Filmed by AMC Studios in Louisiana.
  • Crew: <hr /> Executive producers, Jim Mickle, Nick Damici, Jeremy Platt, Nick Schumaker; writers, Mickle, Damici; director, Mickle. <strong>60MIN</strong>
  • Cast: James Purefoy, Michael Kenneth Williams, Christina Hendricks, Jimmi Simpson, Bill Sage, Pollyanna McIntosh, Neil Sandilands, Jeff Pope