Playwright Annie Baker’s Pulitzer Prize-winning work has sometimes been compared to that of the late Harold Pinter, due to the dramatically and emotionally charged pauses in her dialogue. Yet it might be more accurate, if similarly reductive, to describe her as the anti-David Mamet. Whereas Mr. Mamet is famous for staccato exchanges that furnish a streetwise, often masculine vibe to his work, Ms. Baker’s approach, in musical terms, tends to be more largo — slower in pace and stately, but with deceptive bites contained in both the words and the silences.

This is especially true in Ms. Baker’s latest effort, “Infinite Life,” a one-act piece set at what appears to be a sort of homeopathic clinic in Northern California. The inpatients, most of them older women suffering from debilitating ailments, have been relegated to water or juice fasts for periods of a week or longer. The scenic design, by the design collective dots, consists of lawn chairs where these characters spend most of their days, reserving whatever physical energy they have left.

Director James Macdonald establishes a tone of peaceful languor at first. The women walk slowly to their places, one by one, and then shuffle off to their rooms at night, their movements suggesting a dreamlike dance. Only one lingers in the dark: the youngest, at 47, who is named Sofi. The spelling, indicated at the beginning, is only one vowel removed from the term for an Islamic practice emphasizing introspection and the search for a close connection with God over secular pursuits.

Ms. Baker’s Sofi, played by a winsome and poignant Christina Kirk, is in many ways a more worldly creature. She’s the one tasked with announcing the sudden shifts in time Ms. Baker uses to continually, craftily snap us out of any reverie induced by the soft-spoken conversation and periods of quiet, punctuated by birdsong in Bray Poor’s sound design. (Isabella Byrd’s lighting can be equally subtle or more flamboyant, taking us from early to mid-afternoon or midnight to morning in a literal flash.) 

Sofi’s particular affliction, a bladder condition, makes it difficult for her to urinate. (Be warned that if graphic depictions of bodily functions put you off, this is not your kind of show.) Yet Sofi is more deeply disturbed, she eventually discloses, by her inability to have an orgasm without experiencing excruciating pain afterward. It’s “like some punishment or something,” she muses. “In a fairy tale. The witch cursed me.” 

Then again, the corporeal, the spiritual, and the mystical are inextricably intertwined in “Infinite Life” — which is also, I should point out here, a very funny play, and a fine showcase for all its cast members. They include the duly treasured veterans Kristine Nielsen, who is hilarious and touching as Ginnie, a brashly curious flight attendant; and Marylouise Burke, who lends her indelible genius to the role of Eileen, a matron whose frail appearance and delicate demeanor belie a staunch religious faith.  

Brenda Pressley and Mia Katigbak are also excellent as, respectively, Elaine, who can match Ginnie’s bluntness, if not her lack of discretion; and Yvette, who documents a staggering list of health catastrophes in a perversely, deliciously comical monologue. 

There’s one male interloper, Nelson, a finance bro who walks around shirtless and, in Pete Simpson’s slick portrait, demonstrates about as much empathy for the ladies as that description suggests. Sofi is nonetheless drawn to him, and Ms. Kirk and Mr. Simpson manage a slow-burn chemistry in a vexing, mesmerizing scene that finds intimacy in a most unlikely form.

Yet it’s the bond that Sofi gradually forges with Eileen, a woman with whom she has nothing in common on the surface, that gives this play its final and most profound moment of grace. Eileen confides that she once believed pain to be a trick of carnality, a consequence of “the belief in matter and not spirit.” 

When Sofi does not dismiss this, Eileen makes a more surprising confession, and we are reminded that none of us, in fact, can be reduced to either matter or spirit. In capturing the conflict-prone but complementary relationship between the two, Ms. Baker has given us a work of lyrical beauty, humor, and insight.