A young British couple are driving through France on holiday when they stop for gas. He runs in to pay, she stays in the car. When he returns her car door has been left open, but she's not inside. No one ever sees her again.
Ten years later he's engaged to be married; he's happy, and his past is only a tiny part his life now. Until he comes home from work and finds his new wife-to-be is sitting on their sofa. She's turning something over in her fingers, holding it up to the light. Something that would have no worth to anyone else, something only he and she would know about because his wife is the sister of his missing first love.
As more and more questions are raised, their marriage becomes strained. Has his first love somehow come back to him after all this time? Or is the person who took her playing games with his mind?