El misterio de la carretera de Sintra

On July 23, 1870, the Lisbon "Diario de Noticias" inserted a last-minute note that read as follows: "About to close our edition, we have received a singular letter. It is an unsigned letter sent by post. to our editorial staff. It begins a wonderful narrative about a horrible and mysterious event. The interest it arouses and its literary quality determine us to transcribe such an interesting document in its entirety, which we will do tomorrow Sunday ". And indeed, the next day, July 24, the people of Lisbon, who were happily preparing to witness a parade commemorating the entry of the Liberal Army, were startled by their usual drowsiness with the reading of that first piece of news contributed by an unknown doctor X, apparently witness, and partly protagonist, of the sensational mystery that from that very day began to be known as "The mystery of the Sintra road".