"Black Snake Moan" is an odd little number. It tries to be a lot of things at different times, but isn't particularly successful in any genre. The humor, what there is of it, is subdued by characters who in many ways are tragic figures. Regrettably, the drama of said characters is unconvincing due to a premise that is daffy and just plain awkward. The best chance for resonance is in the platonic love story at the film's center, but this, too, stays so low-key in emotion and muddled in its intentions that only a few isolated moments of truth squeak through.

Samuel L. Jackson (2006's "Snakes on a Plane") and Christina Ricci (2005's "Cursed") play admirably against-type in performances that are braver than the movie they're stuck in. Jackson is Lazarus, a lonely, God-fearing man who has just been unceremoniously dumped by younger wife Rose (Adriane Lenox). Ricci is Rae, a lost soul herself whose chronic nymphomania is unleashed once beloved boyfriend Ronnie (Justin Timberlake) heads off for the military. When a night of loose sex and partying leaves Rae beat up and passed out on the side of a dirt road, Lazarus takes her in while she recuperates. Pretty soon Rae's sex addiction becomes obvious to Lazarus, and when she finally awakes finds herself chained at the waist to the radiator. Rae's initial defiance and Lazarus' vow to cure her of her "wickedness" slowly but surely leads to a mutually redemptive relationship that both of them desperately need.

Written and directed by Craig Brewer (2005's "Hustle & Flow"), "Black Snake Moan" is difficult to pin down. A lurid Deep South-set potboiler in which nothing really boils aside from the steamy blues music that permeates the soundtrack, the film keeps one's attention but leaves the viewer feeling indifferent and at arm's length from the offbeat characters' conflicts. Yes, Rae inspires Lazarus to pursue his passion for performing music, and yes, Lazarus rehabilitates Rae to the point where she can finally stand up for herself and face her deadbeat mother (Kim Richards) about the sexual abuse she suffered as a child, but neither story point adds up to much in the long run.

Hindering the would-be soulful bond between Lazarus and Rae is a lack of meaningful interaction between the two; they share almost all of their screen time together, and yet there is never a full sense of how and why they relate to each other so perfectly. The one scene that threatens to bring a bittersweet poignancy to the proceedings—Lazarus plays the guitar while Rae angelically sings "This Little Light of Mine"—is mucked up by culminating with a deceptive plot turn involving Ronnie that should have been axed in the editing room.

The script is a mess, but star turns from Samuel L. Jackson and Christina Ricci cannot be faulted. Jackson underplays Lazarus as a beaten-down man on the verge of throwing in the towel, but sneaks in some priceless deadpan line deliveries that shade in his personality. Wearing next to nothing for half the movie, Ricci has rarely looked so vibrant and beautiful onscreen, and that's even with the black eye she sports throughout. You can tell by watching her that she relishes portraying the multiple facets of the severely troubled Rae, but the way the character is written often wavers too close to caricature to appropriately care about her well-being. The supporting cast is peripheral, with S. Epatha Merkerson (1999's "Random Hearts") a warm, wholly likable presence as Angela, a pharmacist who takes a liking to Lazarus, and Justin Timberlake (2007's "Alpha Dog") an annoyance as Ronnie. Timberlake is okay with what he is given, but his role serves only as an unnecessary plot device.

"Black Snake Moan" ends on a predictable yet ambiguous note that puts into question Rae's character arc, or lack thereof. Because of this, and because Rae and Ronnie never develop as a believable couple, the arrival of the end credits bring about a feeling of dissatisfaction. What was the point writer-director Craig Brewer was trying to make? "Black Snake Moan," which, come to think of it, resembles a lesser version of 2004's respectively flawed "A Love Song for Bobby Long," is too tonally schizophrenic and narratively murky to ever offer an answer.