''Once a thing is known it can never be unknown.'' By day Frances Hinton works in a medical library, by night she haunts the room of a West London mansion flat. Everything changes, however, when she is adopted by charming Nick and his dazzling wife Alix. They draw her into their tight circle of friends. Suddenly, Frances'' life is full and ripe with new engagements. But too late, Frances realises that she may be only a play thing, to be picked up and discarded once used. And that just one act in defiance of Alix''s wishes could see her lose everything . . .