The Unfaithful Wife (1969) DVD

As the title suggests, Claude Chabrol's slow-burning psychological thriller is inspired by the actions of an unfaithful wife. However, he's primarily interested in the reaction of her husband after he hires a private detective to confirm his suspicions and reveal her lover's name and address. Naturally, he decides to pay him a visit - but, in typical Chabrol fashion, the resulting encounter doesn't play out as one might expect, and culminates in a virtuoso display of sustained suspense that's worthy of Hitchcock himself, especially when a normally trivial road accident threatens to ruin everything.

Michel Bouquet is outstanding as the cuckolded Charles, desperately trying to maintain his carefully-constructed façade of bourgeois unflappability as his life's former certainties start crumbling - but so too is Stéphane Audran as a woman who still genuinely loves her husband, and will do anything to keep their family together, even after the police start asking awkward questions.