A divertissement in the form of a puzzle, Claude Lelouch’s “Roman de gare” is more ephemeral contraption than anything else, but it’s an engaging enough contrivance. The film is basically a series of fragmentary stories about interconnected characters who may be real, or figures in a novel, or literary creations based on actual people—or a bit of all three. And the shards of each are shuffled in terms not only of narrative but of chronology as well. If there were any dramatic heft to what was happening, the process of sorting everything out might be something of a chore. As it is, though, Lelouch brings an airiness to his conceit, and it gingerly carries you along to a conclusion that really has no resonance despite the fact that it includes a death. Nothing much matters in the picture. But since that’s evident from the start you can just relax and enjoy the twisty ride, which Lelouch and his cast conduct with a reasonable degree of charm. The result is akin to “The Last of Shiela,” the puzzle picture made by Stephen Sondheim, Anthony Perkins, Herbert Ross and an all-star cast back in 1973. Nobody could accuse it of depth, either, but it was still a good deal of fun.

The central character is an enigmatic fellow called either Pierre or Louis, depending on the situation. Played by short, squinty Dominique Pinon, he’s first encountered at a highway stop, where he entertains passing kids with sleights of hand and watches as Huguette (Audrey Dana) is abandoned by her fiance after they’ve had a fight while driving to her parents’ farm. She’s either a hairdresser or a hooker. Pierre/Louis offers her a ride and eventually is persuaded to pose as her boyfriend so she won’t be embarrassed with her family. At one point he claims to be the ghostwriter of Huguette’s favorite novelist Judith Ralitzer (Fanny Ardant), whom we see in a prologue touting her latest opus on a TV interview show, but later denies it. In fact he may be a Paris schoolteacher who’s abandoned his wife (who in turn falls for the detective she approaches about his disappearance). Or that woman’s little brother. Or he may be an escaped serial killer known as The Magician. Or he may be more than one of the above.

Or not only he but everyone else could be characters in Ralitzer’s new book, or composites in the novel who are based on actual people. It’s to her yacht that the narrative turns after a sojourn at Huguette’s family farm. There who’s who is ostensibly laid out, leading to what might be a murder, suicide or accidental death, a confrontation between the writer and a fan, and a final twist that leads to the demise of another character.

Or does it? The way “Roman de gare” is constructed, the line between “truth” and “falsehood” barely exists. Of course, everything that happens on the screen is fiction anyway, so it doesn’t really matter. This is a lighthearted piece, essentially an exercise in Pirandello territory in which the blurring of reality and illusion and the theme of self-identify are central, but not so much considered as juggled about as though they were props in one of The Magician’s tricks. There’s no depth or resonance to what happens in the picture; it’s all surface effect.

But that doesn’t mean that it’s isn’t reasonably enjoyable. The movie has some bright writing, and a cast that seizes on the better lines and situations with relish. Pinon is especially strong, with his wry, enigmatic attitude the glue that holds everything together, but the others are good too. And while Lelouch’s touch isn’t ideally light, he and editors Charlotte Lecoeur and Stephane Mazalaigue keep things moving along jauntily for the most part. Kudos are also due cinematographer Gerard de Battista, whose widescreen lensing revels in the locations on the coast and remote rural areas, but also uses interiors well.

In the end “Roman de gare” doesn’t amount to much; it’s like a French pastry that melts in your mouth so quickly that it barely registers going down. But the touch of sweetness lingers.