Tony Walton wraps the riddle of Harold Pinter's Ashes to Ashes in a scenic mystery of his own. For the 45-minute play about a middle-aged Englishwoman recalling Holocaust-like horrors for her baffled husband--or is she imagining them?--he creates a room that evaporates.

Walton's muted interior for the Roundabout Theatre Company production went on view in February (and plays through May 9) at the small Gramercy Theatre on East 23rd Sreet while his splashy, kinetic set for Annie Get Your Gun was previewing at the Marquis Theatre on Broadway. Director Karel Reisz told Walton it was important that the couple's room should disappear rather than simply fade into darkness. "It shouldn't have a 'science fiction' feeling," Reisz said, "it should be a slow melting away, with the audience not really aware of how it's happening. But it does happen, and at a certain point they realize they are, so to speak, inside her head."

The playwright offers few clues about where his characters are, and fewer about who they are. "A house in the country. Ground-floor room. A large window. Garden beyond. Two armchairs. Two lamps. Early evening. Summer."--even Pinter's stage directions have pauses. He stipulates that the lamplight intensifies as the room darkens: "By the end of the play, the room and the garden beyond are only dimly defined." Then a Pinteresque zinger: "The lamplight has become very bright but does not illuminate the room."

To meet Reisz's requirements and achieve what Walton calls Pinter's "Magritte-like imagery," he and lighting designer Richard Pilbrow devised a masterly scenic illusion. "I designed the walls of the room to function as giant lightboxes," Walton says. The wall frames were covered with a translucent, computer-printed wallpaper clad in black scrim. At the preset and throughout the first half of the play, the walls are lit from behind, but, paradoxically, appear opaque. As the backlight fades, front lighting on the scrim makes the walls darken. "The bright lamp light in the room produces an illogical--and perhaps puzzling--blackness on the walls," Walton notes. He specified steel framing for the wall construction to prevent shadows from support braces and frame edges.

The Gramercy was originally a movie house. Reisz, Walton, and Pilbrow were concerned that its long shoebox shape might diminish the intimacy needed for a play in which the action is entirely psychological. So the designer swung the corner of the room around sharply, tilted it at a precarious angle, and pushed it toward the audience like a projectile. The unadorned window grid in the upstage corner suggests prison bars.

"We exceeded Actors' Eq uity's permissible degree of raking in the knowledge that one half of the two-character cast would be the remarkable actress Lindsay Duncan, who is British-trained and familiar with raked stages of all sorts," says Walton, who is himself British-born and trained. The husband is played by American actor David Strathairn, who Walton calls "enormously gifted--and game," adding, "Actors' Equity was somewhat appeased by learning that both actors would be seated throughout much of the play."

Against the rake of the floor, Walton and Pilbrow suspended a lighting grid at the opposing angle. The audience stares at a couple caught in a set of open jaws. The set's forced perspective and what Walton calls "the strangely undressed walls" required an equally bold carpet. "We made an enlargement of a much smaller and more tightly detailed rug," Walton says, "to achieve a quality of recognition that would be simultaneously unsettling." The room is as undressed as the walls. Arrayed on the carpet are twin upholstered chairs, one with a side table. The chairs look unyielding rather than comfortable. At the margins of the room are two floor lamps, a drink cart, and a towering plant. The objects appear as isolated as their owners, islands adrift in a figured sea.

Walton gold-leafed the table top and lampshades to bring "a clang of visual energy and warmth to the early scenes," he says, and then allowed them to "gradually retreat into invisibility." The lampshades' opacity hid rather than revealed light, and their peculiar cone shapes were a sly evocation of a very particular English middle-class taste.

Designing costumes along with setting, Walton dressed the characters to reflect the furniture's isolated look. The wife wears a sleeveless, summery dress that makes her naked shoulders and neck seem vulnerable. The dress's confining cut and clinging fabric emphasize the fullness of her bust, belly, and buttocks, echoing the play's imagery of erotic violence. In contrast, the husband's wintery turtleneck jersey and tweed sport coat suggests an intellectual insulated from his own emotional life as well as his wife.

By the end, when Pilbrow's lighting has crystallized the wife's face to a frozen whiteness in a black void, and sound designer G. Thomas Clark has reduced her voice to a ghostly reverberation, Tony Walton's set has vanished into the play's dark matter.