Wrong Mountain, David Hirson's ambitious but ailing new Broadway play which opened January 13, has its own "bête".

He's obscure poet Henry Dennett, astonishingly played by Ron Rifkin, who like some schoolmarmish, smalltime variation of Shakespeare's King Lear, rails and rants against the kind of financially-rewarding establishment success that he's never even tried to attain.

The only respite that the poet - and, for that matter, the audience - gets from Dennett's tirade against everything he's not comes only after a play he's written on a dare becomes an unexpected hit. Suddenly, Dennett becomes kinder and he seems to find a peace of mind that has always eluded him. In fact, a huge tapeworm, literally and figuratively gnawing at his intestines and psyche, vanishes in the glow of public applause and his newfound sense of self-worth.

Unfortunately, however, despite Hirson's obvious gift for lyrical language and soaring story - both of which might have helped ensure the success of a scholarly treatise - Wrong Mountain is disappointing as a play.

If Hirson, whose short-lived play La Bête famously flopped on Broadway in 1991, had shown more of Dennett's ascent from living hell to relative heaven, then this current comedy-drama would have been a lot more illuminating and entertaining.

That said, I must nevertheless strongly disagree with Clive Barnes, my erstwhile colleague at the New York Post, when he says in his review of Wrong Mountain that "the best performance of the evening came from a toy electric train, which unfortunately made only two appearances."

The train, with its gleaming stainless steel coaches streaming through a snowcapped mountain range, indeed gets a smattering of applause. But there's absolutely no question that Rifkin turns in a riveting, if largely one-note performance. And most of the rest of the cast, including Michael Winters, who plays a self-satisfied prig of a commercial Broadway playwright who's engaged to Dennett's ex-wife, Daniel Davis, as the bombastic play festival director, and Beth Dixon, as Dennett's former wife, are excellent in problematic roles.

In one of many telling lines that seem to rebound straight back to the spectacular failure of La Bête, one of the two other playwrights competing in Wrong Mountain's play-within-a-play play festival competition says "I don't believe that any true artist is capable of mediocrity in any form. Fiasco, maybe."

And, like La Bête, which actually got mixed reviews, not pans, Wrong Mountain is neither mediocre nor fiasco. It just seems to be as unfinished as it is unfulfilling. For me, it's almost as if Hirson's tightly-drawn lead character - who often leaves you breathless in reaction to his unwavering anger - seems to cry out for some further attempt by the playwright to make us care as much about him than we do, say, for Willy Loman in Arthur Miller's Death of a Salesman.

Nevertheless, to Hirson's credit - or perhaps to his dramaturgical detriment - this vitriolic, Frankenstein-like portrait of an artist as a misanthrope remains virtually constant right up until the less-than-bitter end.

As Hirson told Playbill in an interview, "On the surface, Dennett is an entirely loathsome character, but the degree of his misanthropy suggests the degree to which life has wounded him. One of the things that makes him human, and not just some horrible monster, is that he's been deeply wounded. And he responds in a way that makes him almost magnificent in his suffering and failure."

The trouble is that most poets don't end up on "The Today Show" or "Good Morning America," being interviewed by Diane Sawyer. Moreover, given Dennett has chosen his bed - his profession, such as it is - we can't understand why he feels so deeply wounded. Did, for instance, his wife leave him because he's poor or because he didn't share any part of his poetic vision?

Maybe next time - I ferverently hope there will be a next time - Hirson will create someone we really care about. David Hirson may never be an Arthur Miller, let alone Shakespeare, but this talented playwright has a great play in him that's still crying to come out.