The Elevator Resides in 501 - Beau Livre

Between 1978 and 1981, Sophie Calle clandestinely explored the then disused Grand Hôtel d'Orsay. She settled in room 501 and proceeded to photograph and collect whatever objects she encountered in the deserted hotel, following in the footsteps of a mysterious former handyman, Oddo. More than 40 years later, room 501 has disappeared from the building : it is just another elevator in the Musée d'Orsay.
What happened to room 501 and to Mr. Oddo, the ghosts of Orsay ?