The Mystery of the Enchanted Crypt (Original title: El misterio de la cripta embrujada, 1979) is a hilarious novel that has its roots in the Spanish picaresque genre. It opens with the mysterious disappearance of several teenagers from the convent school of the Lazaristas Mothers of San Gervasio in Barcelona. The investigation is narrated by an unnamed inmate from a mental hospital who is forced to help the police in order to solve the case.
The action takes place within a few days in the spring of 1977, six years after the disappearance of the first girl in the school; it has a linear structure and nineteen chapters written in chronological order. In the first two we learned what has happened; chapters three to eighteen are devoted to the investigation and in the last chapter we arrived at the solution.
Eduardo Mendoza y los laberintos de la realidad por José F. Colmeiro (in Spanish)