France, the 1920s. In a hotel by the sea, a magic show distracts idle customers. Marta, an unhappy young woman with her jealous husband, agrees to participate in a disappearance number and takes the opportunity to disappear for good. To respond to the husband demanding the return of his wife, the magician places a box in his hands, telling him that she is inside. However, he must only open it if he has absolute faith in it, otherwise it will disappear forever. Doubt then sets in with Charles...