In this adaptation of the play "Waterloo Bridge," Gaby (Leslie Caron) is an elegant French ballerina who is performing in World War II-era London. There, a chance encounter introduces her to Gregory Wendell (John Kerr), a passionate young soldier. Gaby warms to him over their day together, and the two besotted young lovers agree to marry as soon as Gregory returns from service. But when Gaby discovers that her fiancé has died in battle, she hopelessly turns to prostitution.