A good rule of thumb about whether or not to watch a movie from the mid-1930s on into the 1950s is to ask, “Is Basil Rathbone in it?” The vulpine baritone with the steely gaze and plummy line-readings dressed up a lot more than Sherlock Holmes mysteries or Errol Flynn swashbucklers. As villains or ghosts (“A Christmas Carol”), he couldn’t help but class up the joint.

It’s a pity RKO didn’t pay his electric presence its proper due in “Heartbeat,” a Sam Wood-directed Ginger Rogers romance filmed just after the war and set in pre-war Paris. A not-quite-frothy romance that tried to pass off 36 year-old Ginger as “just escaped from reform school,” it paired her up with debonair French expat Jean-Pierre Aumont, whom Hollywood had to regard as a “Well, if you can’t get Paul Henried” choice for much of his time there. They looked that much alike.

But the movie this might have been is in “Heartbeat’s” crackling first scenes. Rogers’ gamine Arlette shows up at a Parisian school run by Professor Aristide, and he’s played with an officious and greedy twinkle by Rathbone.

Professor Aristide is “a respectable gentleman,” smoking jacket-respectable, polished and efficient. He’s headmaster at a boarding school for pickpockets.

“Nimble fingers are the great essential!”

He uses a vast collection of manikins to train the street thieves of Paris, many of whom just arrived from abroad or the provinces, all of them eager to learn. One hilarious bit — one training dummy is wired up like the kids’ game “Operation,” which could practically have been inspired by this movie. Make a blunder picking this dummy’s pocket — lifting his watch or plucking his stick-pin — he lights up.

As you might guess of a “respectable” man who sends his pupils out to pilfer polite society, Aristide’s a stickler for speech.

“How many times do I have to remind you that I will NOT tolerate slang in my classroom?”

Trainee Arlette is valued because she can sell the “It wasn’t ME” protest, upon being caught, better than anybody, and she can pass for honest. But damned if her career and the movie don’t go wrong shortly after she’s sent on her first outing.

Adolphe Menjou plays an ambassador whose pearl stick-pin is just irresistible to Arlette. She plucks it, but he drolly and wordlessly tracks her off the street car, into the cinema, merely snapping his fingers to demand its return.

This ambassador doesn’t turn her in to the authorities. He drags her home, dresses her up, passes her off as a colleague’s “niece” and puts her to work to steal one item off one particular guest at an embassy reception. That guest turns out to be the dashing young bachelor Pierre de Roche (Aumont). And between dancing with him to rob him and dancing with him again to return the purloined timepiece, he is smitten, even if she is just looking for enough money to “buy a husband” for a marriage-in-name-only that will keep her out of reform school.

The complications, the “courtship” snags, the obstacles presented by friends in this posh world de Roche travels in, Arlette’s engagement and a pleasant pause for Ginger to sing a limp little ditty, “Can You Guess?” don’t add up to much of anything, or anything nearly as interesting as a life of petty crime.

The characters in that half of the movie are ably played by familiar faces like Melville Cooper, Mona Harris, Eduardo Cianelli and Henry Stephenson. But there’s no pop to any of these performances or scenes. It’s a nicely-designed but drab “star vehicle” romance with elegant clothes, upper class predicaments and a very cute terrier.

The heartbeat of “Heartbeat” is the school for artful dodgers and its headmaster. He’s got to keep his charges out of trouble and turn them not just into convincing thieves, but credible liars.

“When I lie, everybody knows it,” new recruit Yves (Mikhail Rasumny) laments. “I should go into politics, where it doesn’t matter!”

Wood, whose workmanlike and rarely flashy career included “Goodbye, Mr. Chips,” “Pride of the Yankees,” the grand farce “Casanova Brown” and Rogers’ classic, “Kitty Foyle,” had to see there was a better movie built around the ongoing pickpocket operation and its “Oliver Twist” hold on Arlette.

But RKO, determined to extract maximum value out of Rogers and an accomplished supporting cast — at least some of whom were anxious to get back to Europe now that the war was over, produced a far more star-centered vehicle with a lot less going for it, maintaining Rogers’ profile but not challenging her or the audience with something edgier, grittier and funnier.

Based on a French 1940 romantic drama “Battement de couer,” “Heartbeat” isn’t a bad film, but more of a light and watchable programmer than the prestige picture RKO wanted or the larcenous farce it could have been.

Big names like Menjou have little to do. And every scene that doesn’t have Rathbone booming instructions, scolding his student pickpockets or collecting their “collections” at day’s end is an opportunity lost.

Rating: “approved”

Cast: Ginger Rogers, Basil Rathbone, Jean-Pierre Aumont, Adolphe Menjou, Mona Harris, Melville Cooper and Mikhail Rasumny

Directed by Sam Wood, scripted by Morrie Ryskind, Hans Wilhelm, Max Kolpé and Michel Duran, adapted from the French film “Battement de couer.” An RKO release on Tubi, Amazon, other streamers

Running time: 1:42