Bet you can’t keep ahead of the twists in the sitcom play “Ripcord,” David Lindsay-Abaire’s “Odd Couple” romp for two women thrust together in a senior living complex. They are roommates who don’t get along: One’s sweet, the other’s sour. But they are zesty enough to make a bet to settle which of them will rule the roost, and their competitive schemes zing the play in unexpected directions.

Claire Schoonover (as Marilyn, the sweet one) and Deb Gottesman (sour Abby) are ideally matched in Megan Thrift’s clever staging at Keegan Theatre, where a shoestring budget doesn’t hamper ad­ven­ture scenes during Halloween and, in one of the best capers, on an airplane. Abby is the early focus, and Gottesman measures out Abby’s toxic complaints and insults with precision as the cranky loner plots to have the small nursing home room to herself.

Gottesman is on familiar turf; she was in the 2000 premiere of Lindsay-Abaire’s dotty “Wonder of the World” at Woolly Mammoth. The hilarity with Abby comes from how frigid and controlled Gottesman can be, jabbing icicles at Marilyn or at Scotty, the kindhearted resident aide who delivers medicine and tries to keep peace.

Schoonover is unbreakably peppy as Marilyn; the bet is that Abby can’t make Marilyn angry, and Schoonover’s beaming smile and resilient happiness are like nails on a chalkboard for Gottesman’s surly Abby. Marilyn wins if she can make Abby frightened; the emotional freight of the wager gives the play an option for depth.

“Ripcord,” a 2015 play getting its area professional premiere at Keegan, doesn’t entirely cash in on that possibility. The piece is a return to early form for Lindsay-Abaire, better known for his working-class drama “Good People” and the Pulitzer-winning “Rabbit Hole.” The antic “Fuddy Meers” was his theatrical breakthrough, with a woman laboring to pronounce “fun house mirrors.” That view of people pushed to distorted extremes is so emphatic in “Ripcord” that Marilyn’s daughter (a confident figure, as played by Kari Ginsburg) and son-in-law (Oscar Ceville, as the off-balance partner) have a “safe” word they have to use several times as they get lured into Marilyn and Abby’s bizarre shenanigans.

Particularly falling short is the sudden family backstory involving Abby and her estranged son, Benjamin (a persuasively unguarded Robert Bowen Smith), a history so heavy that it shoves the comic train well off the tracks in the second act. The gutsiness of the play is seeing how Abby and Marilyn prank each other so intensely and so personally that it really hurts, but the balance is mis-calibrated here.

Thrift’s show is consistently good, though, at the big and little moments that catch you unaware. Matthew J. Keenan’s drab senior living set transforms into a haunted house at one point, with nightmare action that’s evocatively staged. Jared Shamberger gives a lovely performance as the tenderhearted Scotty goaded into a nifty gear shift; Shamberger gets one of the biggest laughs in a show full of gags that go “Gotcha!”

Ripcord, by David Lindsay-Abaire. Directed by Megan Thrift. Sound and projections design, Veronica J. Lancaster; costumes, Alison Samantha Johnson; lights, Jessica Steadman; props design, Cindy Landrum Jacobs. About two hours. Through July 6 at Keegan Theatre, 1742 Church St. NW. $36-$58. 202-265-3767 or