In Paris under German occupation in 1942, a young and impoverished pianist named Sophie gets a job as live-in aide and accompanist to a famous and glamorous singer, Irène.

As Irène's possessive husband and manager, Charles, a devious businessman collaborating with the Vichy regime and the Nazis, wrestles with his conscience, the highly impressionable Sophie becomes obsessively close to Irène, living life vicariously through Irène's musical and amorous exploits, particularly an affair with Jacques, a handsome member of the Resistance.

So Charles takes the pair by foot over the Pyrenees into neutral Spain, from where they make their way by sea to London.

There Irène can resume her life as fêted prima donna and lover of Jacques who, as she knew all along, is now based there.

Sophie is a silent witness to the deepening unhappiness of Charles, a fish out of water in an alien environment, and the increasingly reckless behaviour of Irène.