Teenager Paul (Dermithe) shares a bedroom and a suggestively close relationship with his overbearing older sister Elisabeth (Stéphane). When the delicate Paul is injured in a snowball fight by Dargelos (Cosima), a schoolboy he is attracted to, doctor's orders are for bed rest, much to Elisabeth's delight. Able to spend virtually all their time together, the siblings engage in intense, secretive mind games and soon ensnare Paul's friend Gérard (Bernard) in their unwholesome web. When Elisabeth brings home a boarder named Agathe (also played by Cosima), conflicting attractions ensue and the quartet of troubled youths spins into chaos.

This unlikely collaboration between famed crime-film director Melville and surrealist legend Cocteau (who wrote the screenplay, adapted from his own novel) throbs with a tension that reflects the artists' differing creative approaches. The dreamlike atmosphere and undercurrent of dangerous sexuality are pure Cocteau, where the inventive camera angles and slightly noir sensibility are Melville signatures. Stéphane, nominated for a BAFTA for her intense performance, shines as the near-crazed sister consumed by unhealthy urges and driven to nefarious acts. These enfants may be quite terrible, but their bad behavior makes for one heady movie experience.