Juan, David's best friend, has lost his shadow. He cannot find it and doesn't know when it has disappeared. At least he has David to help him. Together they will try to recover it by all means. Will they get it? And you, have you seen Juan's shadow? 
All the proceeds from this book go to the Niemann-Pick Foundation in Spain, which finances various research projects to improve the quality of life of patients and to find treatments for this rare, degenerative and highly disabling disease which today has no cure.