One verb pops up with ironic regularity in "Benefactors," the new English import by Michael Frayn that opened Sunday at the Brooks Atkinson Theatre. It is the verb "to help" and it assumes increasingly darker implications each time it is uttered. If they were asked to defend their actions over the play's 15-year time span, Frayn's four characters, two married couples, would say they were merely extending a helping hand. In truth, they are strangling one another and smothering their own dreams in the process.

At first glimpse, "Benefactors" seems a radical switch from Frayn's previous hit, "Noises Off," in which a third-rate troupe of thespians, touring the English provinces, makes mincemeat of a cheesy sex farce. "Noises Off" is explosive slapstick comedy. The reverberations in "Benefactors" are subtler and they run deeper. But a similar view of humanity prevails. The destinies of David and Jane and their sorry next-door neighbors, Colin and Sheila, are as entwined as those hapless stooges in "Noises Off," who feed one another the wrong lines and are forever misplacing their props. In both case, the upshot is similar: rubble.

With Sam Waterston, Glenn Close, Mary Beth Hurt and Simon Jones giving performances that go from the good to the inspired, "Benefactors" single-handedly raises the collective IQ of Broadway by about 20 points. The dramaturgy is as sharp and precise and clean as the skyscrapers that David (Waterston) is designing to replace 15 acres of slum housing in and around London's Basuto Road. But it's the deceptive sharpness you get when mirrored walls come together at odd angles and produce an infinity of optical illusions.

The motives of Frayn's characters are not opaque. David believes devoutly in the possibility of social change through architecture. His wife Jane (Close), seemingly the perfect helpmate, not only organizes their household efficiently but has energy to spare for the neighbors. And it's obvious that Sheila (Hurt) needs assistance. A hopeless mess, she can't get a meal on the table or dress her children. Her marriage to Colin (Jones) is souring fast, as is Colin himself, a two-bit journalist who has developed a sardonic streak to compensate for his failures. Why shouldn't David and Jane, sure of their marriage and their purpose in life, help these two "middle-aged children"?

Once that decision is taken, however, motives will suddenly cease to be quite so simple, and basic allegiances will be turned inside out. David's grand redevelopment scheme will encounter mounting resistance, much of it fueled by Colin. After volunteering to do her husband's field work, Jane will begin hatching doubts of her own. Meanwhile, inept Sheila, hired as David's part-time secretary, will turn into his most zealous supporter. Both marriages will come unraveled under the strain, and the housing project, when it finally gets built, will be a sad betrayal of the idealism that inspired it.

No one really sets out to produce so much wreckage -- not even Colin, who will lead the street protests against the Basuto Road project. He, after all, is "helping" the poor people, whose homes are marked for demolition. Midway through the play, he deserts Sheila. Jane finally finds him, squatting in one of the tenements. "Welcome to the war," he says with a thin smile. More than urban renewal is in question. Benefaction itself is Frayn's subject and he finds it as dangerous as a land mine. Both the helper and the helped can go up in the blast.

The play is constructed with devious brilliance. The characters, talking long after the fact, take turns relating the story, the implications of which they are still trying to comprehend. Along the way, the critical events and conversations are acted out as they occurred. The switch between then and now is deftly staged by director Michael Blakemore, but the real deftness is Frayn's: at each juncture, he forces us to revise our notions of who is really helping whom.

On the surface, "Benefactors" never looks to be less than clear-cut, yet in the final analysis, all four characters prove tantalizingly ambiguous. They subscribe to change and believe it can be rationally effected. But they are outpaced by events and invariably hoodwinked by their feelings. As the battle progresses, the line between disinterest and self-interest is constantly being redrawn in their souls.

At first, Close's radiant blond beauty seems to cast sunshine over the play. Seemingly indefatigable, she approaches each little travail with the understanding and good humor of one who's got it all together. Without violating that image, however, Close neatly explores the flip side -- the cool self-sufficiency, the impatience, the gathering frustration -- so that by the end you can see her kinship with the play's most sinister character, Colin. As Jones plays him, he is all snipe and sneer, but so confidently understated that the character is doubly chilling. Even at his most loathsome moments, however, Jones never entirely relinquishes the residual boyishness that constitutes his redemption.

Hurt, whose self-deprecating giggles will dissolve into tears of futility, is impressive as the rudderless Sheila. Waterston, however, can't seem to hold onto a consistent English accent or the inflections that go with it. He has an intrinsic affability that is right for David, a creature who only wants to be liked by the world, until that world comes tumbling down around him. But he remains the odd actor out, sometimes jeopardizing, if not destroying, the tight sense of ensemble playing that would unleash "Benefactors' " fullest powers.

Intentionally or inadvertently, you see, these characters are dragging one another down into a nether world of confusion. For all its passing humor, "Benefactors" is a deeply pessimistic work about people living and working together. But then, as Colin observes, "you look up on a clear night and there's only a dusting of light in all creation. It's a dark universe."

Benefactors, by Michael Frayn. Directed by Michael Blakemore. Set, Michael Annals; costumes, John Dunn; lighting, Martin Aronstein. With Glenn Close, Sam Waterston, Mary Beth Hurt, Simon Jones. At the Brooks Atkinson Theatre in New York.