Paradoxical as it may seem, it is possible to believe the actors on a stage and not believe the play in which they're appearing. As evidence, I submit "Danny and the Deep Blue Sea," the two-character drama by John Patrick Shanley, which the New Arts Theatre has mounted for a run through July 27.

Everything that Brian Hemmingsen and Kathryn Kelley are doing as a pair of crazed misfits who meet in a dingy Bronx bar, spend a night together and find respite from their demons in one another's arms, strikes me as truthful and even affecting. But the 90-minute play is full of psychological holes, improbable character transformations and a hokey sentimentality that belies the rough, no-expletives-deleted dialogue.

Danny is a 31-year-old bruiser whose only response to the world is to lash out at it with his bare knuckles. The truckers he works with by day call him the Beast and, indeed, he just may have killed a man the previous night. Roberta is a 29-year-old single mother, whose miserable life includes an instance of fellatio with her father. Guilt-ridden and neurotic, she seems only a breath away from suicide.

What Shanley wants to show us is how, by joining hands, these two make their way back to the land of the living. Their hard shells, you see, are merely protection for the softness within. For all their crass talk, they are still capable of poetic insight. The world has dumped on them, but if only they could take charge of their destinies, maybe things would be different.

This is fertile, if not particularly original, turf for drama. The trouble is that "Danny and the Deep Blue Sea," while more than a vignette, is not developed enough to qualify as a persuasive play. The characters tend to lurch from one state of soul to the next. Defense mechanisms crumble too quickly. Revelations come too easily. Loutish Danny -- nearly inarticulate with rage when we first meet him -- shows an unlikely aptitude for amateur psychiatry when he roots out and absolves the shame in Roberta's soul. For her part, she flip-flops between hopelessness and high-strung aggression. It's not enough to say they're half mad. Shanley needs to tell us far more.

All the more impressive, then, that Hemmingsen and Kelley manage to give the performances they do. Fresh from Horizon's "Last Days of the Dixie Girl Cafe," Hemmingsen continues to have an uncanny way of suggesting the sensitivities of the brute. And while I fear he is letting himself get typecast, there is something touching about his clumsily concentrated struggle with words and emotions. It's almost as if he is trying to dissect a butterfly's wing with a crowbar. Kelley is perhaps too fine a beauty for Roberta, but the actress has boldly coarsened her manner and looks, and her innate delicacy functions as an ironic undercoating to garishness. Pushing bravely though the material until they come out on the other side, the two succeed in forging some real bonds.

John Neville-Andrews has directed the pair forthrightly on a triangular thrust stage at All Souls Church. There's no hiding from an audience in such close quarters and you can tell right off that these performers aren't cheating. The playwright is.

Danny and the Deep Blue Sea. By John Patrick Shanley. Directed by John Neville-Andrews. Set, Michael Layton; lighting, Daniel MacLean Wagner. With Brian Hemmingsen and Kathryn Kelley. At the New Arts Theater (All Souls Church) through July 27.