Paul Vincent O'Connor and Joseph Patrick O'Malley Photo by David Allen

But scratch a little beneath the surface, and Caryl Churchill's 2002 play is just as much an exploration of the perils of nostalgia. Salter (an appropriately conflicted Paul Vincent O'Connor), the father of Bernard (Joseph Patrick O'Malley)—and, it follows, of all the clones—is seeking to reinvent the past, to start over with a new Bernard in order to expiate his guilt over having not done a very good job in raising the first Bernard. The question here is just as much "can you hit rewind on existence?" as it is "are we defined more by nature or by nurture?"

This 55-minute two-hander roars unrelentingly through its subject matter, exploring both the insecurities of the men who discover there are an unknown number of beings walking the globe who are genetically identical to them. Salter, their "father," seems empathetic to their plight: "Walk around the corner and see yourself? You could get a heart attack. Because if that's me over there, who am I?" But he's also angry at the scientists who stole his son's DNA to make multiple clones, regularly threatening to sue. "They've damaged your uniqueness," he says.

But have they? Even with clones, small differences—in the environment in which they were raised, the food they ate, the activities they engaged in—will all ultimately individualize each of the "reproductions." Fittingly, the three clones Churchill presents—the original Bernard, plus a Bernard 2 and a Michael Black—present as very different personalities. It's almost as if they are working through a variant of Elisabeth Kübler-Ross's stages of grief: Bernard 2 in denial and depression, Bernard 1 in anger and bargaining, and Michael Black having achieved acceptance.

Both actors deliver wonderfully moving and insightful performances. Joseph Patrick O'Malley does marvelous work playing each of the three clones so that we in the audience can both sense the differences between them and better understand the issues Churchill raises in her text. His Bernard 1 is delightfully twitchy and anxious, and O'Malley gives him a revealing bit of physical business when he takes a glass and repeatedly lifts it and sets it down, with a slight twisting motion each time, as though it were a cookie cutter. Paul Vincent O'Connor plays Salter as a tremendously conflicted figure, filled with both regret and optimism. Salter failed as a father, but his attempts to rewrite history only end in more tragedy, and the cumulative effect of these errors are evident in O'Connor's careworn expressions.

Despite the excellence of the performances (on a starkly lovely set by Michael Locher) and the skilled direction from Barbara Damashek, A Number is ultimately too chilly to be satisfying emotionally, and too shallow to be intellectually compelling. It's another excellent production from a talented team, but the source material sadly fails to engage.

A Number, through May 6, 2018, at Harry's Upstage at the Aurora Theatre Company, 2081 Addison Street, Berkeley CA. Shows are Tuesdays-Wednesdays at 7:00 p.m., Thursdays-Saturdays at 8:00 p.m., and Sundays at 2:00 p.m. and 7:00p.m. Tickets are $33-$65. Tickets and additional information are available at www.auroratheatre.org or by calling 510-843-4822.