Lisa Newman's photographic memory and linguistic skills make her no ordinary girl. On leaving school she goes to France to teach English to the Dubois children, but when World War II breaks out, Lisa reluctantly decides her place is with her mother and brother in their Somerset village. Then her old employer turns up with the charismatic Etienne Arnaud, to offer her a unique and dangerous proposition: she is to return to France, assuming the role of Etienne's cousin. As Lisette Arnaud, Lisa has no difficulty is passing herself off as a Frenchwoman - far harder is resisting her feelings for Etienne...