In the cellars he finds a scrap of paper hidden between stones. Its ink is faded, its date is 1721, and its handwriting is unmistakably his own. Experts confirm the paper’s age and the signature-like strokes; soon he is convinced that some earlier self was betrayed, imprisoned, and left a treasure behind.
As he hunts for the truth, ordinary Paris turns uncanny: a wax mask, a portrait, a violet cat, and a name that surfaces from the past. His wife worries, his spiritualist friend theorizes, and someone else seems to be following the same trail. To claim the fortune—or the identity—he must discover what happened on a long-ago first of April.