During high summer, Franck (Pierre De Ladonchamps) is one of several regulars at a lakeside beach, a secluded spot frequented by naturists and cruising gay men. Between swims, while exchanging pleasantries with his unprepossessing chum Henri (Patrick d’Assumçao), Franck first spies the athletic, moustachioed Michel (Christophe Paou).

Franck sees the same hunk again the very next day, when he watches, frozen, while Michel drowns one of his sexual partners. Instead of reporting the murder, Franck lies to the investigating officer. The sharp- featured cop (Jérôme Chappatte) can’t understand how the lakeside crew return to bareback business-as-usual in the bushes so soon after a murder: “You guys have a strange way of loving each other sometimes.”

That goes double for Franck, who soon embarks on a passionate, intensely physical relationship with Michel. The menace that his new lover exudes and the possibility that he might well bump him off only seems to draw Franck in further.

It’s a sex and death thing, people. There’s something hari kari about those tumbles in the grove long before Michel gets to work. Claire Mathon’s brilliant cinematography finds an appositely sinister glare in the shimmering water and sunny skies.

Alain Guiraude rightly took home the Best Director prize from the Un Certain Regard section and the Queer Palm at Cannes last year for this intriguing Hitchcockian thriller. Guiraude finds interesting textures in the men's behavioural codes and the odd formality of the meat market: "You've got a great cock. Well, I have to go," says a post-fumble Henri before offering a handshake.

Mannered exchanges and repetitive rhythms – how they park their cars, the rules that govern courtship and coupling –make Michel’s actions all the more shocking. Never more so than during the final act, when the mounting tension explodes into a messy, somewhat unsatisfactory conclusion.

Viewers who like to reach for smelling salts should take heed: Stranger by the Lake is characterised by explicit sex (performed by body doubles) and near constant nakedness. There's a whole mess of squishy undercarriage from a great many unflattering angles.

The dangly, un-photoshopped nudity adds to the sensation that the action – and that is the right word – is taking place during the '70s. Michel's facial hair, the unprotected sex, and the need to hide away suggest that we're watching a contemporaneous companion piece to William's Friedkin's similarly themed Cruising . They deserve each other – in a good way.