'The world is made of floors. Floors are connected by stairs and made of rooms. Rooms are connected by corridors. And all the floors form the World...' Such is the theory developed by Toto, the siamese head of a child whose mother has locked away in a family manor, where he has been walled-in since his birth. Between endless corridor exploration, private schooling and fatherly Mausoleum visits, the brothers never questioned the limits of their world. Until one day, when, obsessed by a strange light, seen by accident, they decide to find the its end.