Cheltenham Center for the Arts, 439 Ashbourne Rd., Cheltenham, through Nov. 5, 379-4027.

It's 1977. Jerry (Leonard Haas) and Robert (Paul Meshejian) are best friends. Robert publishes novels by writers whom Jerry, a literary agent, represents. From 1968 to 1977, Jerry has been having an affair with Robert's wife Emma (Susan Wilder), spending weekday afternoons with her in a flat they rent together.

Just about all there is to Harold Pinter's 1978 play Betrayal is contained in the title -- except that the betrayal to which the title refers is not only Jerry's betrayal of his best friend, but the equally large betrayals of trust in all three relationships in the triangle.

We, along with the characters, learn of these other betrayals as we see the events -- before, during and after the affair -- unfold, in roughly reverse chronological order, over the course of this swift play (only 75 minutes, without intermission, in Ken Marini's production at Cheltenham).

Jerry doesn't know that Robert knows about the affair. Emma hasn't told Jerry that Robert knows. And, while they chat with each other (Jerry and Emma in their secret flat, Jerry and Robert in various pubs and restaurants, all three in one or the other's living rooms) over glasses of scotch or red wine or vodka or corvo bianco, they don't reveal to each other how much they know that the other doesn't about who knows how much about whom. And they refer to events -- Jerry, in Robert's kitchen (or is it his own?), throwing into the air Robert and Emma's daughter; Robert, on a 1973 trip to Venice with Emma, taking an early-morning speedboat to Torcello, sitting alone and reading Yeats -- that may or may not have taken place, and that certainly did not have the same significance to each of the people remembering them.

This is, in short, a wonderful play, filled with seething emotions: of longing, confusion, pain, and deep, deep senses of betrayal, of all kinds and at all levels.

The actors at Cheltenham, hampered somewhat by their unnecessary British accents, generally get these emotions. But, of the three, only Meshejian succeeds in keeping these emotions below the surface, letting them bubble up only in the arch of an eyebrow or the subtle sarcasm of a passing wisecrack.

And so, with all the emotions on the table, they all miss the bigger emotional issues of the play: the terror of remaining a stranger to one's nearest and dearest and to oneself, of standing at the frontiers of what Jerry calls "the state of catatonia... where the reigning prince is the prince of emptiness, the prince of absence, the prince of desolation.''"

The set, by David P. Gordon, wisely features a bed -- the site of betrayal -- upstage throughout the play. And the costumes, by Laila Kjoersvik-Swanson, featuring crushed velvet pantsuits, dirndls, Ban-roll waists, and Dr. Scholl sandals, is as evocative of the '70s as are the men's sideburns.

-- Cary M. Mazer