Death ain't quite what it used to be in the Signature Theatre Company's revival of John Guare's Landscape of the Body. In fact, it's downright impossible to determine from what's onstage whether it's supposed to be a worse fate than living.

The confusion is due to a young woman named Rosalie, who died a year ago but hasn't let that stand in her way. She's returned from the afterlife to sing a little, dance a little, and deliver moral lessons about a woman who had to find anything. And the vantage point of death offers Rosalie the ability to illuminate the darker corners of life, while having a ball.

Sporting a white and gold dress (the costume designer is Miranda Hoffman) and her usual long, blonde tresses, Sherie Rene Scott transforms Rosalie into a glimmering force of nature, a capricious firefly flitting through a dark evening. Whether shimmying across the stage with the vaguely satiric poise of a reluctant entertainer, or brassily belting the sly Brechtian musical interludes Guare himself has composed, Scott takes no prisoners when she takes full charge of the stage.

But this proves a mixed blessing in a production in which practically everything else goes wrong. As directed by Michael Greif, apparently while blindfolded, this Landscape of the Body emphasizes to an obscene degree the revitalizing powers of death and destruction. Scott, whose musical-comedy talents have never been put to better use, polishes this idea to its fullest sheen, but without her castmates providing performances that can temper Rosalie's bravura, the play's message becomes morbid instead of inspirational.

The story should center on Rosalie's sister, Betty (Lili Taylor), whose son recently died and was found decapitated, floating off an abandoned pier in Greenwich Village. (The show is set in 1977, and this crime's resemblance to the Village's "Bag Murders" of the period is not coincidental.) We first see Betty on the deck of a ferry to Nantucket, where she meets the police investigator once assigned to her case, Captain Marvin Holahan (Paul Sparks), under suspicious conditions designed to make us question her innocence or guilt from the get-go.

But as Rosalie guides us through the past two years of Betty's life, Taylor can't maintain Betty's necessary balance between maternal concern and self-involvement. Worse, the more we're introduced to the others in her life - her son Bert (Stephen Scott Scarpulla), the Southern gentleman and bona-fide mental case she ran off with (Jonathan Fried), the eccentric owner of the scam phone business where she earned her living (Bernard White) - the more Taylor's Betty becomes a supporting player in her own saga.

Ideally, she should be the clearest representation of the urban blight infecting the city and the characters. Everyone else in the play either dies or is spiritually or morally eroded by the play's events, which range from the ironic to the unfortunate or bloody (and, often, all three). Betty must be the one in whom the future of the city and its inhabitants are reflected: Her choices, about life and death and what to do with what she chooses, should ground this swirling enigma of a play, which is otherwise held together by little more than Rosalie's narration and the pervasive hopelessness everyone is suffering from.

That tenuous connection to reality, which enables the fluidity of motion across time and space that Rosalie oversees, is what gives the play its potential power. Guare marshals that chaos into surprisingly bewitching order: He asks of us only that we give him the benefit of the doubt that the pieces will eventually come together, and of the director only that there be a believable emotional foundation capable of keeping the structural irregularities in check.

Greif, however, hasn't exerted a firm enough hand on the play or on his colleagues. Neither he, set designer Allen Moyer, nor lighting designer Howell Binkley are able to ensure that the audience is always aware of what is happening where and when: Set pieces tend toward the ugly or the nonspecific, and few scenes are lit or paced in ways that make their location or significance clear. Characterizations like Paul Sparks's inanely bumbling Holahan, Scarpulla's "aw shucks" Bert, and Fried's borderline-autistic Southern white knight, do nothing to contribute to a unified universe.

Taylor's efforts to flesh out Betty fail as the actress strains against her natural instinct to make the character likeable. This technique has served her well in certain roles - most hauntingly, in The New Group's 2003 production of Aunt Dan and Lemon - but it's devastating for Betty, who must intrigue us, but also needs an outer shell of untrustworthiness that cracks only as the full details of her unhappy life are revealed. With Taylor, what you see is, at most, what you get.

Rosalie benefits from a scrutable Betty, and is easier able to break the shackles of her assumed sororal responsibility and just step forward to enlighten and entertain us. Scott is more than up to the challenge of making ingratiating a role typically filled with brittlely acidic types (Peg Murray and Candy Buckley are two of its better-known essayers). Scott's a shimmering joy here, providing the energizing sense of life the play, like Betty, should thrive on.

She makes this a Landscape of the Body we've never seen before, and aren't likely to see again. For now, death never looked so good.

Landscape of the Body
Through May 21
Signature Theatre Company's Peter Norton Space, 555 West 42nd Street between 10th & 11th Avenues
Tickets: 212.244.PLAY (7529)