Is 94-year-old June Squibb the next Tom Cruise?

Maybe not, but 'Thelma' scoots along as a delightful action comedy

If Harrison Ford can still be an action star at 80, and Arnold Schwarzenegger at 76, is it really such a leap to give 94-year-old June Squibb her own “Mission: Impossible”-style franchise? Who needs to drive a BMW M3 or a souped-up electric yellow Fiat when you have a much more maneuverable mobility scooter?

That’s the idea behind writer-director Josh Margolin’s delightful action comedy, which gives Squibb her best role since she was nominated for an Oscar for Alexander Payne’s “Nebraska.” Though the movie has fun with action-movie conventions, it never goes over the top into parody territory. This is just one sweet old granny who won’t back down.

Thelma lives in Los Angeles, doted on by her 24-year-old grandson Danny (Fred Hechinger). Margolin has said in interviews that their relationship is based on his own grandmother, and it’s a rarity in films to see such a warm cross-generational relationship like this. Usually adult grandkids are depicted as aloof and self-involved, but Danny genuinely loves his grandma, and she worries that he’s a bit of a lost soul.

Those worries seem to prove valid when Thelma gets a phone call, supposedly from Danny, saying that he’s been arrested and his defense attorney needs $10,000 to bail him out. In a tizzy, Thelma sends the money. But Danny is fine. Thelma has fallen victim to the sort of phone scam that preys on the elderly, one that is distressingly common in real life.

But Thelma is not the sort of person who takes that sort of swindle sitting down. With the help of her late husband’s friend Ben (the late Richard Roundtree in an affecting final role) and Ben’s high-powered motorized scooter, Thelma putters across the city on a mission of revenge, following the clues that lead her to the scammers’ seedy HQ.

(Photos courtesy of Magnolia Pictures)

There are plenty of nods to action movies, especially “Mission: Impossible” — Thelma is inspired by Tom Cruise’s DIY stunts in “Fallout” to take matters into her own hands. And at times the film is genuinely exciting (propelled by an absolute banger of a score by Alex Chuba) as Thelma and Ben cross the city and get in and out of one scrape after another. In hot pursuit behind them are Danny and his worried parents (a droll Parker Posey and Clark Gregg).

But Margolin never pushes Thelma to do more than we could reasonably expect a fit, sharp nonagenarian to do. And the film does slow down at times to delve into the hard realities of aging, as Thelma and Ben bemoan the friends and spouses they lost along the way, or Thelma runs into random strangers who she thinks she recognizes.

Squibb is so funny and vulnerable as Thelma, and tough when she needs to be. Riding along with her (at 15-25 miles per hour) is a delight.

“Thelma” is now playing in theaters. In Madison, it is playing at Marcus Point, Marcus Palace, and AMC Fitchburg 18.