The first thing you notice about La Piscine  is the heat. It hangs over everything: the still water, the long afternoons, the bodies stretched out in various states of undress. Nothing moves quickly. Conversations drift. Time loosens. On the surface, Jacques Deray's 1969 thriller feels almost weightless: a film in which little seems to happen, beyond a group of beautiful people circling one another around a pool. But beneath the languor, a quiet tension tightens, communicated less through...