More often than not, black-box theaters turn out to be black-hole theaters — ill-equipped basement pits where neophyte playwrights and tyro directors are indulged in unsupervised play. That is so not the case at Roundabout Underground, which Roundabout a.d. Todd Haimes and curator Robyn Goodman run with artistic acumen and a firm professional fist. “Tigers Be Still,” Kim Rosenstock’s quirky little drama-comedy about two terminally depressed families, gets the royal treatment here. Helmer Sam Gold’s sensitive script-wrangling and the canny work of a super-duper cast keep this charming but oh-so-delicate play from disintegrating in the harsh light of day.

Rosenstock’s domestic material may be familiar — unhappy parents, miserable children — but her idiosyncratic treatment invites us to examine all this suburban angst with fresh eyes. The oddball characters are so sympathetic, and played with such tender understanding, it’s hard to resist her directive — even when she throws a runaway tiger into the goofy mix of situational realism and absurdist farce.

Think of that improbable tiger as a handy metaphor for the repressed longings of these narcoleptic characters to get on with their lives — if only they could find the energy to crawl out of the bed/sofa/closet where they have taken refuge from their individual miseries.

Sherry, the young art therapist played with endearing naivete by Halley Feiffer (“subUrbia”), managed to roll off the couch when her mother prevailed upon her old beau, the high-school principal, to give the girl a job teaching an art class and mentoring his own troubled son. Now Sherry hops around the house like a baby bird noisily greeting the rosy dawn, chirpily urging her mother (in traumatic shock ever since her husband walked out) to get out of bed and her sister (in acute despair ever since her fiance called off their wedding) to give up the sofa.

Although the mother of this pathetic household stays out of sight in an upstairs bedroom, we see quite a lot of Sherry’s weepy sister, Grace (Natasha Lyonne), who has made a nest of the couch. In between raids on her former boyfriend’s apartment to steal his prized possessions, she devours chocolate and obsessively watches “Top Gun.” Even as she romps in the comic absurdity of Grace’s flamboyant tantrums, Lyonne (“Love, Loss & What I Wore”) makes us aware of the deep hurt that fuels her over-the-top rage.

The two sisters share the stage (rather awkwardly, it must be said) with another, equally unhappy family. As the head of this motherless household, Joseph Moore, the uncomplaining school principal played with gentle authority by Reed Birney, can’t get a civil word out of his sullen teenage son, Zack (the terrifically talented John Magaro), who spends most of his time sitting on the floor of his dead mother’s shoe closet.

The bizarre therapy sessions in which Sherry sweetly tries to get some response from the uncommunicative Zach are so beautifully played by Feiffer and Magaro that you don’t know whether to laugh or cry — which seems to be the reaction Gold was aiming for by directing these bittersweet scenes in some emotional half-light between pathos and farce.

Rosenstock writes clever comic dialogue in a voice that is too smart to be cute. There’s something both sad and wise, after all, about re-defining a “mellow” mood as meaning “paralyzed with depression.”

And while Sherry might not impress anyone as a professionally rigorous therapist, the popsicle-stick art project she assigns as class work has as much therapeutic value for someone suffering from terminal sadness as, say, writing a play about a tiger.

Tigers Be Still

Harold & Miriam Steinberg Center for Theater/Black Box; 62 seats; $20 top

  • Production: NEW YORK A Roundabout (Underground) Theater presentation of a play in one act by Kim Rosenstock. Directed by Sam Gold. Grace - Natasha Lyonne
  • Crew: Sets and costumes, Dane Laffrey; lighting, Japhy Weidman; sound, Fitz Patton; production stage manager, Kyle Gates. Reviewed Oct. 3, 2010. Opened Oct. 6. Running time: 1 HOUR, 45 MIN.
  • Cast: Sherry - Halley Feiffer Joseph - Reed Birney Zack - John Magaro