It all began one violent night at the lake house. But now, nearly a decade later, Alex (François Cluzet) has learned that the gruesome murder that evening of his wife, Margot (Marie-Josée Croze), was not what it appeared to be. And until “Tell No One,” the new film by the French director Guillaume Canet, rather laboriously tries to explain itself, this hot-blooded thriller does an excellent job of spinning a very complex tale.

Clocking in at 125 minutes, “Tell No One” comes with at least two plot twists too many, and a tell-all finale that practically merits its own intermission. But otherwise, Mr. Canet, who adapted Harlan Coben’s popular page-turner with screenwriter Philippe Lefebvre, strikes a near-perfect balance of suspense and raw emotion.

Alex, a pediatrician in a working-class suburb of Paris, is marking the eighth anniversary of his wife’s death when he gets a mysterious e-mail suggesting she might be alive. The same day, two corpses are discovered near the place where Margot’s father, the local police chief, identified her body, and the gendarmes reopen the case. But the new evidence supports their original suspicion — that Alex was the killer.

Stressful multitasking ensues as Alex works to decode the e-mail and keep himself out of custody. Fooled by a planted gun, the cops come after him just as he’s about to meet a correspondent he’s sure is Margot. The terse-looking Mr. Cluzet (who played a desperate lover with equal skill a decade ago in Claude Chabrol’s “L’Enfer”) makes Alex a compelling fugitive; he may not be a marathon man à la Harrison Ford, but he’s more believable, and an extended police chase sequence through an immigrant neighborhood is more than just a nail-biter — it palpitates with amour fou.

There are other nice surprises. Aided in his flight by the tough-guy father (Gilles Lellouche) of a patient he once saved, Alex enters one of the fortress-like housing projects of Paris that one doesn’t often see stateside in French movies. With a couple of deft touches, Mr. Canet transforms the setting from an edgy backdrop to a lived-in place with its own social codes.

The bluesy soundtrack by M (France’s pop star of the moment) is more than effective, and there’s talent to burn in the high-profile cast that Mr. Canet — who is better known as an actor and, perhaps, as Oscar-winner Marion Cotillard’s boyfriend — has assembled. Marina Hands, as Alex’s sister, and Ms. Croze (both of whom were in Julian Schnabel’s “The Diving Bell and the Butterfly”) are barely used, though it only takes a scene or two involving the crystalline Ms. Croze to understand that her disappearance from a man’s life could wreck him. Also appearing are Kristin Scott Thomas as Alex’s best friend and confidant, Nathalie Baye as his lawyer, Jean Rochefort as a horse-breeding politician, and the director himself as the politician’s spoiled son. Only later does the latter family’s sordid role in the conspiracy become clear. Of course, that could be said of just about everything in the film. Also trying to untangle what happened on the night Margot was killed is an assiduous police inspector (François Berléand), who becomes convinced Alex is innocent. Playing him off a young, impulsive partner (Mr. Lefebvre) may be a cliché, but it is nevertheless very satisfying when his cooler head prevails.

As the film zigzags toward its conclusion, even attentive viewers will likely miss a few turns. Finally, a long-winded confession delivers the unlikely truth. (It also contains more flashbacks than a season of “Highlander.”) Does this overripe mélange of thriller and cri de coeur straighten out every knot in the end? Couldn’t tell you. But it packs a pretty good wallop anyway.