Esteban Navarro Soriano 
Chess Player [EPUB ebook] 

A newlywed couple buys a second-hand apartment. In the storage room there are belongings of the owner, who died ten years ago, and the intermediary of the sale (a friend of the current owner) tells them that once they buy the apartment, they can get rid of those effects. Before closing the deal, she gives them a succulent discount with only one condition: they will have to keep the trunk with three locks that is in the storage room until the owner (who lives in a nursing home) dies.