Two's company, three's a shroud in this utterly suspenseful story of diabolical doings and undoings. At a dingy boarding school for boys, the callous headmaster Michel (Paul Meurisse) reigns over his wards with sadistic pleasure. Even his frail wife Christina (Véra Clouzot), a former nun, cowers before him. When Michel's icy mistress, played by frosty femme Simone Signoret, feels equally terrorized, the two women join forces to dispatch the unprincipled principal. The deed is done and the scoundrel disposed of in the school's murky pool, but soon it is apparent that the watery depths bear no body. It is said that Clouzot grabbed the rights to the novel over the protests of Alfred Hitchcock, who had to settle for another Boileau/Narcejac creation released as Vertigo. But Clouzot proceeds without a hitch, heightening the hysteria as the two wrong-doing women bicker over motives, doubting their own deadly course. There is water, water everywhere in this shocking suspenser, from the tepid tub and turbid pool, to the pall of dampness that envelops all. Diabolique takes you to the lower depths. You'll be gasping when you resurface.