Here are some of the ways you know that Stranger By The Lake (Strand) is a French film, not an American one: the subject matter (gay men cruising and having sex near a lake), the nudity (some of the men at the beach sunbathe naked), the depiction of gay sex (graphic, including erections and orgasms, and realistic to say the least), and men in Speedos (need more be said?).
Attractive and fit gay man Franck (Pierre Deladonchamps), makes small talk with dumpy straight man Henri (Patrick d'Assumçao) at the beach on a summer day. Franck used to sell vegetables at the market and is trying to figure out his next move, while the newly single Henri is a logger. Their conversation ends abruptly when Franck sees mustached Michel (Christophe Paou), a man in whom he's interested, and follows him into the wooded area, littered with condoms, condom wrappers and crumpled tissues, where an assortment of men have either paired off or are hoping to do so. But Franck's pursuit of Michel hits a road block when he suspects that Ramiere (François Labarthe) is Michel's boyfriend.
A pattern is soon established. Franck arrives daily at the lake's parking lot and takes his place on the beach next to Henri. Franck and Henri become better acquainted, with Henri's eyes being opened to the various nuances of gay culture and behavior. More often than not, Franck wanders into the woods to test his own wood making skills.
Things take an unexpected, decidedly dark turn when, late one afternoon after the beach emptied of sunbathers, Franck witnesses Michel drown Ramiere in the lake. The only remaining traces of the dead boyfriend? His little red Peugot left in the parking lot for days on end, as well as his towel, clothes and shoes on the beach.
But that doesn't prevent Franck from returning to the lake, day after day. When Michel approaches Franck, he is initially hesitant (he did witness Michel drown his boyfriend!) and then gives in and has sex with him. And the next day, too! Unsafe sex to boot! But what the heck, you're doing it with a murderer anyway.