Well, Broadway can still surprise, and I found "Thou Shalt Not," which opened last week and was eviscerated by most of the critics, better than I had expected. To be sure, the prospects for a musical this dark — a young woman conspires with her lover to murder her husband — were never very bright, especially so in a dark year like this one. But even in cheerier times, "Thou Shalt Not" would have needed strong critical support to survive, and the show now appears doomed. But before it departs for the graveyard of Broadway bombs, it deserves a little credit for all it tried and what it achieved.

Zola's tragic story has been updated to post-World War II New Orleans, but the plot's basic outline has been changed little. And that's part of the hurdle the musical faces. This is a show in which the two leads (Craig Bierko and Kate Levering) wind up destroying each other; another character spends the entire second act paralyzed by a stroke; and yet another doesn't come to life until after he's dead. That "Thou Shalt Not" doesn't become a complete downer is a tribute largely to the flavorful music of Harry Connick Jr., the jazzman making his first foray into Broadway. Connick does best, not surprisingly, with the Dixieland-style numbers meant to evoke the period. But he also shows impressive range, with Sondheim-esque character songs, a sweet children's ditty ("Tug Boat"), and the jabbing bass notes that italicize the moments of violence and sexual heat.

The second thing that transports this musical is Stroman's lyrical and sensuous choreography, wonderfully danced by Levering, the former co-star of "42nd Street." In the climactic seduction scene in Therese's bedroom, Levering slithers and writhes and wraps her legs around Bierko as seductively as Cyd Charisse used to envelop Gene Kelly. Not only is this a rare Broadway musical where the dance numbers actually illuminate character and enhance the story; it's also one of the few that manages to portray sexual passion convincingly. Seldom do I believe that a couple onstage are really attracted to each other. Here I do.

The faults of the show lie mainly in David Thompson's book, which is too perfunctory with the minor characters and can't really bring off the couple's Act II decline into guilt and self-destruction. Bierko and Levering, moreover, are too bland as actors to really give this story the emotional punch it is striving for. Norbert Leo Butz, against all odds, becomes the standout in the cast, turning from sickly victim into a song-and-dance ghost, who comments ironically on the couple's plight in a swinging, Cy Colemanesque number, "Oh! Ain't That Sweet," that almost stops the show. The irony is somewhat jarring, since nothing in the oh-so-serious first act prepares us for it. Still, it achieves the purpose of giving us an attitude toward the tragic denouement, apart from sheer depression, which is not a good thing to be humming on your way out of a Broadway musical.

I wasn't exactly humming on the way out of "Thou Shalt Not." But I was happy to have seen a musical that takes on a nearly impossible task — creating an entertaining musical out of grim tragedy — with originality and flair. It deserves more than a one-way ticket to the morgue.