Robert Bowen Smith and Kerri Rambow star in “In a Word,” a production of Lauren Yee’s play by the Hub Theatre. (DJ Corey Photography)

Certainty has eluded Fiona since her young son was kidnapped a few years back. Still, she’s reasonably sure that she is missing a child and not a garment. The detective investigating the case has other ideas, however. “Is he this sweater?” he asks Fiona, producing a tiny pullover from a box. When she demurs, he urges her to think again. “One time, lady lost her son,” he remembers. “They found him as a rock. . . . Cold, hard, igneous. But it was him.”

Reality swerves regularly into absurdism in “In a Word,” Lauren Yee’s achingly poetic and quirky play about grief and loss. Now on view in a resonant Hub Theatre production, adroitly directed by Matt Bassett, the play imagines a world in which people, moments in time, and bits of language transform and echo in unsettling and treacherous ways. People become sweaters or rocks. A detective becomes a missing child. A troubled employee’s leave of absence becomes a “leaf” of absence, and then an entire “tree of absence” growing in a back yard.

The hallucinatory details and wordplay hint at the disorientation Fiona experiences after the kidnapping of 7-year-old Tristan, her adopted son. Tristan had been a difficult child, and Fiona’s memories of occasionally resenting him add to her confusion after he vanishes. As the detective brightly remarks while devouring a cantaloupe that may, or may not, be key evidence in the case: “More than enough guilt to go around.”

The bewildering properties of guilt and bereavement register powerfully in the Hub production, which achieves an artful balance between dark comedy and eloquently understated drama. Kerri Rambow teases out the stubbornness and dazed anger that make Fiona’s grief her own singular burden. Colin Hovde is a valuably measured presence as Fiona’s husband, Guy, who has come to terms somewhat with the loss of their son.

Robert Bowen Smith does a fine job juggling all the play’s other roles, including the unnervingly unpredictable detective and Andy, Guy’s best friend, whose gossipy comments about Tristan’s birth mother (“She joined the army.. . . /She flew the coop./She popped the weasel./She put the bomp in the bompbahbompbah.”) illustrate how the play’s naturalistic dialogue sometimes veers into poignant, jazzy poetry. Smith particularly aces his portrait of Tristan, who’s sweet one moment and throwing tantrums the next.

Scenic designer Betsy Zuck bolsters the story’s intimacy with a living-room set that’s rendered slightly dreamlike by an overhanging autumnal tree branch. Catherine Girardi’s lighting adds clarity as the narrative glides through time and degrees of the surreal. Due to a technical difficulty, Patrick Calhoun’s sound design was not audible throughout the performance I attended, but the show’s acting, pacing and lighting were so well-pitched and confident that I was unaware of the problem until informed about it later.

In 2013, the Hub mounted Yee’s “The Hatmaker’s Wife” (formerly titled “A Man, His Wife, and His Hat”), a daringly kooky play whose characters included a Cheetos-eating golem and a talking wall. The more-focused “In a Word” (which premiered in 2015) manifests the same audacious whimsy but directs it more effectively toward the exploration of deep human emotion. At some point, a Tree of Absence grows in most people’s lives.

“In a Word,” by Lauren Yee. Directed by Matt Bassett; costume design, Maria Vetsch; composer and sound designer, Patrick Calhoun; props design, Deb Crerie and Kay Rzasa; assistant director, Douglas Robinson. 80 minutes. Tickets: $15-$30. Through April 24 at The John Swayze Theatre at the New School of Northern Virginia, 9431 Silver King Court, Fairfax. Call 800-494-8497 or visit www.thehubtheatre.org.