We begin with Agnes and Tobias, a middle-aged couple having cocktails in their upper-middle-class living room. Janice Duclos and Timothy Crowe quickly establish the wary, fleeting equilibrium of two longtime partners who know just how easy it is to fall off their shared and fraying tightrope. Duclos's Agnes soon tips the balance with a long, unsettling rumination on whether she will go mad someday -- or whether, in fact, she already has.
That question hangs, unspoken, over the rest of the play's three acts. Is this a normal, tidy, suburban family with the usual dents and dings, or is it a house full of lunatics? Or (what often feels like Albee's answer) do those two possibilities amount to the same thing?
Even if they could keep their poise on their own, Agnes and Tobias don't get the chance. First there's Agnes's live-in sister, Claire, a boozy sage who proudly declares herself "a drunk," not an alcoholic. Then there's the couple's 36-year-old daughter, Julia, headed home after the breakup of her fourth marriage. And then -- well, it's Albee, so it's time for some unexpected and unwanted guests.
These are Harry and Edna, earlier referred to as Agnes and Tobias's best friends. But they're not here this time for a round of golf or dinner at the club; they've landed on the doorstep, trembling as if dropped from space, because while they were sitting at home they were suddenly overcome by a nameless dread. They'd like to come in.
In fact, it soon transpires, they'd like to move in. And so the balance tilts again, this time more dangerously, as old assumptions about friendship, duty, loyalty, and love start to crack.
Director Kevin Moriarty has assembled a fine cast from the Trinity company, and each performance feels intelligently considered and expertly rendered. Anne Scurria , in particular, makes Claire's every word and gesture ring true; you get this woman's fury, wisdom, and pain, and you even get why she plays the accordion.
For all the hard work, though, the whole thing just feels slightly unreal, and not in a good way. Partly there's a difficulty built into the play. Albee sets "A Delicate Balance" in the present, and Trinity follows that instruction in its (surprisingly frumpy) costuming and decor. But "the present" has a nasty way of turning into the past.
Thus, for example, an Agnes and Tobias in 2007, not 1966, would no longer have a cook on staff; they wouldn't smoke, they wouldn't consider a 36-year-old to be at the end of her childbearing years, and they wouldn't hear "Alcoholics Anonymous" as if it were some wacky, newfangled fad.
Small points, perhaps. But if we are to believe the terror of these people when they realize they've been living on a thin shell of ice over a bottomless pit, we also need to believe, absolutely, that the ice once felt like solid ground. If it never seems real, it's not as scary when it cracks.
Louise Kennedy can be reached at kennedy@globe.com.