Bookseller Laurent Letellier comes across an abandoned handbag on a Parisian street, and feels impelled to return it to its owner. The bag contains no money, phone or contact information. But a small red notebook with handwritten thoughts and jottings reveals a person that Laurent would very much like to meet.

Without even a name to go on, and only a few of her possessions to help him, how is he to find one woman in a city of millions?