Someone once described lovers bound by obsessive love -- desperate, shameless, ego-eroding love -- as a pair of wild animals with fangs permanently sunk deep in each other's neck. Once bitten, they literally can't live any other way -- withdrawal uncorks a lethal blood flow. Besides, it's only by feeding off each other's very life force that either one feels truly, completely alive.

Such a dark, destructive love -- between an Irish shaman and his woman on one level, between an artist and his art on another -- is the life force raging below the hauntingly placid surface of "Faith Healer," Brian Friel's often-revived 1979 play, currently receiving a knockout production at Rep Stage. Superbly cast and intelligently directed, the show immediately strikes the script's mother lode -- a fat vein of some of the human heart's more terrifying and opaque paradoxes.

An accomplished playwright, Friel can still be an acquired taste. His conventional plays are often more lyrical than dramatic, more sentimental than honest; not much really happens, yet his work is too fussily pretty to be considered minimalist. But "Faith Healer" is a series of monologues, and a form that doesn't require standard action allows Friel to concentrate on his considerable strengths -- evoking atmosphere through character and, like Chekhov, suggesting tumultuous emotions underlying the seem like the most banal utterances.

Frank (Nigel Reed), who may or may not be a real faith healer, Grace (Julie-Ann Elliott), his mistress or possibly his wife (it's never clear which), and Teddy (Bruce Nelson), Frank's agent-manager, individually recount the events of "Faith Healer," which have all taken place long ago. A simple template, but it has a trap -- characters talk only about the past, failing to create a theatrical present -- and "Molly Sweeney," Friel's more recent and better known monologue play, fell into it. In "Faith Healer," though, two of the characters are ghosts, and their accounts often differ, usually on some of the more telling, painful details. Grace tells of her stillborn child; Frank later casually says she was barren. Any resemblance to "Rashomon" is probably deliberate: The disparities generate tension.

Not that there's a huge amount of plot. With Teddy arranging the appearances and Grace in tow, Frank toured England, Wales and Scotland for years "healing" people, before coming back home to Ireland. "Nine times out of 10 nothing ever happened," he confesses to us, admitting that he came to doubt whether he ever had any divine powers, and that maybe his successes were just accidents. But during those years he feverishly believed in his powers -- he had to, if they were ever to work at all. And those powers exacted his heart and soul in return.

In the end they also exacted Grace's. When Frank succeeded, he lavished her with all the attention, affection and comforts that a woman from Ireland's upper class felt she deserved, and she couldn't have been happier. When he failed, he took it out on her, and their fighting was as cruel and degrading as their romancing was sweet and passionate. Whatever it was that Frank possessed, it destroyed him and her -- and both went to their destruction willingly.

This potentially depressing tale becomes fascinating largely because Kasi Campbell directs with an eye toward eliciting the characters' individual losses and pain, not whatever bitterness they may still harbor for each other. Ultimately you're left with the difficult and poignant feeling that, however sick and even perverted it was -- and even though Frank possessed a "killer instinct" to serve his talent, as Teddy tells us -- the love between Frank and Grace was real.

As Frank, Reed is a husk of a man who with a mere inflection alternately conveys both the sensitivity and insensitivity an artist must have. One minute you feel he's looking right at you, speaking only to you, and the next minute he's lost somewhere inside his head, though he hasn't taken his eyes off you. As Grace, Elliott is a glass about to shatter: She struggles mightily to hold herself together, leaning heavily on booze and cigarettes as she tells her side of the story. Nelson provides the much-needed comic relief, his Teddy as brash, loud and even vulgar as a seedy showbiz type should be. But he has his own loss, and it seeps through his feigned resignation.

Everything occurs on Milagros Ponce de Leon's expressionistic set of wooden platforms flanked by decrepit picket fences, all set against a blank backdrop. Combined with Dan Covey's shadowy, sepulchral lighting, it creates a world onstage that seems to emanate, all too appropriately, from somewhere between memory and the grave.

Faith Healer, by Brian Friel. Directed by Kasi Campbell. Costumes by Rosemary Pardee; sound, Neil McFadden. Approximately 2 1/2 hours. Through Nov. 24 at Rep Stage, 10901 Little Patuxent Pkwy., Columbia. Call 410-772-4900.

Bruce Nelson and Julie-Ann Elliott as the manager and wife of an Irish shaman in Brian Friel's 1979 play. Nigel Reed conveys both the artist's sensitivity and insensitivity in the title role of Rep Stage's "Faith Healer."