"El clavo" by Pedro Antonio de Alarcón is a detective story published in 1853. Considered the first precedent of the detective genre in Spain, it follows a judge who investigates a mysterious skull pierced with a nail found in a cemetery. As he unravels the murder case, his personal life becomes entangled with the investigation when the prime suspect turns out to be someone he knows intimately. Based on a real case that circulated in nineteenth-century Spanish newspapers, this short novel blends romance with criminal mystery. (This is an automatically generated summary.)