Peter Van Wagner, Ben Hirschhorn and Barbara Kingsley Photo by Kevin Berne

In Jake Brasch's startlingly effective play, The Reservoir, which opened this week at Berkeley Repertory Theatre's Peet's Theatre, the reserves Josh (an undeniably charming Ben Hirschhorn) is seeking are those of the cognitive variety. And not for himself, but for his grandparents, to whom he has attached himself in the hope of helping them ward off the specter of dementia. According to neuroscientists, cognitive resources can be "banked" through physical activity, learning new things, or playing complex brain games, and are considered helpful in delaying the loss of brain function. For Jake, who is taking a year off from NYU to work on his sobriety, is directing his healing efforts at his grandparents while he's actually working on healing himself. "Maybe they can help me start over," he states at one point.

As the play opens (on Afsoon Pajoufar's spare set: four simple chairs and a widescreen projection of a reservoir on the upstage wall), Josh is lying on the shore of a lake, reveling in the "sweet spot" of "not too drunk, not too sober" before moving on to surprise his mother (Brenda Withers), who has had far too much of Josh's alcoholism to be terribly welcoming.

While the relationship with his mother is strained at best–she subjects him to a breathalyzer test when he comes home–his deepest connections are with his grandparents. Although he's out to his Jewish paternal grandparents, Bev (Pamela Reed) and Shrimpy (Peter Van Wagner), his gentile maternal grandfather Hank (Michael Cullen) greets his return with the suggestion that he ought to "stop playing the field" and just choose a girl. Hank's wife Irene (Barbara Kingsley) is already in memory care and non-verbal, but in Josh's imagined dialogue with her she asks, "are we in the same place?," evidently meaning disconnected from reality.

Much of the glory of The Reservoir comes from Brasch's intricate structure and Mike Donahue's directorial skills in translating that structure and Brasch's dialogue into a physical form that seems to take on a life of its own. Much of the play consists of long asides to the audience, as Josh invites us in to the internal monologue of an alcoholic who desperately wants to be sober, yet at the same time yearns for the calm alcohol brings him, how it quiets the angry and dismissive voices in his head.

Despite having his head up his ass (in the words of his Nana Bev), Josh can be surprisingly kind and gentle. He accompanies his grandmother to Jazzercise and cajoles Grandpa Shrimpy into playing brain games, even when Shrimpy himself is having trouble with his Torah portion for his second bar mitzvah at age 83.

Josh is less helpful to his coworker Hugo at the bookstore (where his mother has found him a job), having trouble stocking books. "I used to read voraciously, now I can't even alphabetize." To counteract this deficit, he arranges the books according to smell. At least when he's not reading himself or clocking out early for Jazzercise.

There's so much going on in Josh's life–and head–that the play becomes dense with metaphor and meaning, text and subtext seeming to weave in and out of each other, just as Josh seem to be simultaneously living inside and outside of his head and its thoughts, which are mirrored in Josh's almost constant motion on stage.

All of this action–both internal and external–could easily become tiresome if it weren't for the brilliant performances of each member of the cast. Hirschhorn exudes the energy and confidence of a young man with his life ahead of him, yet also seems to manage letting a deep strain of self-loathing come through. The pain registering on his face when he realizes one of his relapses has caused him to miss an important family event is as undeniably heartrending as the scene that precedes it, with Josh dancing in drunken abandon in a nightclub blaring house music.

Brenda Withers is appropriately chilly as a mother who has seen her son fall again and again, to the point that she has no more energy to lift him back to his feet for "just one more chance." Her stiff posture and folded arms in the early encounters of Josh's recovery will be recognizable to anyone who has had to deal with the horrors of addiction and caregiving. Withers plays several other roles, and inhabits them so seamlessly that, for a while, I wasn't sure it was her, and not another actor, playing them.

Each of the four grandparents are stunning in their own way. Michael Cullen's Hank exudes both a strain of cluelessness about his grandson, mixed with deep love and a sense of betrayal when Josh lets him down. Peter Van Wagner gets some of the biggest laughs of the night with his portrayal of Shrimpy ("Ranch dressing is the sacred jism of the Republican ruling class"), and his slightly stooped posture and skeptical, even kvetch-y, nature seemed perfectly in tune with Brasch's text. There's a moment in act two (minor spoiler) when Shrimpy has trouble with the Torah portion for his second bar mitzvah, but can perfectly chant the portion he performed 70 years prior.

The two grandmothers are almost as different as night and day, yet united in their love for Josh. Barbara Kingsley can bring such joy to her face that it seems to suffuse the theater with warmth and goodwill. And when she descends into dementia, I wanted to rush on stage to hold her hand or provide some bare bit of comfort, so much did she remind me of the last stages of my own mother's life. On the other end of the spectrum is Pamela Reed's Bev, whose training as an electrical engineer shows itself in her rational, common sense approach to Josh's addiction. Reed plays her as a stoic, no-nonsense woman who is still capable of whimsy, joy and possibility. I won't spoil what I think is her best scene, but if you are fortunate enough to see The Reservoir, pay attention to the voices that echo when Bev and Josh holler "I know nothing!" into a mountain canyon; they speak volumes about the impact of family connections in both characters' lives. Finally, Jeffrey Omura plays his roles (including Hugo) with great delicacy and feeling.

I feel I could write volumes about the wonders of The Reservoir, but I shall limit myself to encouraging you to make plans to get to Berkeley and add this amazing bit of theatrical art to your cognitive resources while you can.

The Reservoir runs through October 12, 2025, at Berkeley Repertory Theatre, Peet's Theatre, 2025 Addison Street, Berkeley CA. Shows are Tuesdays and Wednesdays at 7:00pm, Thursdays, Fridays and Saturdays at 8:00 p.m., with matinees Saturdays and Saturdays at 2:00 p.m. There is a matinee on September 18 at 1:00 p.m. (with a talkback session) with no evening show that night. Tickets are $31-$140, with discounts available for those under 35. For tickets and information, please visit www.berkeleyrep.org or call 510-647-2949.