If you're old enough to carry an AARP card, you've been warned about impostor scams in which someone who claims to be your grandchild calls to plead for money to get them out of a jam. While we all think we're too smart to be fooled, countless victims fall for these hoaxes every year. They're even falling for them in novels.

In the delightful "Mrs. Plansky's Revenge," by Spencer Quinn, 71-year-old Loretta Plansky — referred to throughout the novel as Mrs. Plansky — gets a call in the middle of the night from her grandson Will. He's been arrested and his car's been confiscated by the police. In order to get it back, he needs $9,726.18. Even though "Will" doesn't quite sound like himself — it must be the bad connection — she gives him her bank account number, the routing number and worst of all, the account password, "!NorManConQuest!"

Unfortunately, Mrs. Plansky (like many others) uses the same password for all her accounts. Before she can type !NorManConQuest!, her savings account has been emptied of nearly $69,000 and so has her investment fund of more than $3.8 million.

As bleak as this sounds, "Mrs Plansky's Revenge" has a cozyish, comedic feel and Mrs. Plansky is a believable character for whom readers will cheer. A widow living independently, she's an everywoman. She and her late husband, Norm, made their fortune creating and selling the Plansky Toaster Knife. She's a vital, intelligent retiree living in Florida, missing her husband but trying to live a full life. But losing her money and the embarrassment she feels because of it — Quinn does a terrific job plumbing the depths of her shame — unleashes a side of Mrs. Plansky that she didn't know existed.

When the FBI reveals that the scam call may have come from Romania, she packs her ballet flats and a warm coat and flies to Bucharest. After snapping a photo of secret documents at the U.S. embassy, she heads to a small mountain town where this "ordinary older American woman" goes rogue, embraces her inner crimefighter and hatches a plan to steal her money back.

It's hard to say whether anyone in the real world could do what Mrs. Plansky does — flying down a winding mountain road on a motorbike at death-defying speeds or rappelling out of hotel windows — but Quinn, already beloved for his Chet and Bernie series about a man-and-dog crime-fighting duo, has created another lovable character who's sure to win over his already rabid fans.

If this light and funny novel's primary lesson is to hang up on scammers, its bigger and more important message is metaphorical but true: "Don't be a punching bag. Punch!"

Carol Memmott is a writer in Austin, Texas.

Mrs. Plansky's Revenge

By: Spencer Quinn.

Publisher: Forge, 304 pages, $26.99