After picking up her two children from school, Grace Lawson looks through a newly developed set of photographs. She finds an odd one in the pack: a mysterious picture from twenty years ago, showing four strangers she can't identify. But there is one face she recognizes, that of her husband, from before she knew him. When her husband sees the photo that night, he leaves their home and drives off without explanation. She doesn't know where he's going, or why he's leaving. Or if he's coming back.