The Man with the Twisted Lip
Arthur Conan Doyle
 Dr Watson is called upon late at night by a female friend of his wife. Her husband has been absent for several days and, as he is an opium addict, she is sure he has been indulging in a lengthy drug binge in a dangerous East End opium den. Frantic with worry, she seeks Dr. Watson's help in fetching him home. Watson does this, but he also finds his friend Sherlock Holmes in the den, disguised as an old man, trying to extract information about a new case from the addicts in the den. Mr. Neville St. Clair, a respectable and punctual country businessman, has disappeared. Making the matter even more mysterious is that Mrs. St. Clair is quite sure that she saw her husband at a second-floor window of the opium den, in Upper Swandam Lane, a rather rough part of town near the docks. He withdrew into the window immediately, and Mrs. St. Clair is quite sure that there was something very wrong. Naturally, she tries to enter the building, but her way was blocked by the opium den's owner, a Lascar. She quickly fetches the police, but they cannot find Mr. St. Clair. The room, in whose window she saw her husband, is that of a dirty, disfigured beggar, well known to the police, by the name of Hugh Boone. The police are about to put this report down a mistake of some kind when Mrs. St. Clair spots and identifies a box of wooden bricks that her husband said he would buy for their son. A further search turns up some of her husband's clothes. Later, his coat, with the pockets full of several pounds' worth of pennies and halfpennies, is found in the Thames just below the building. The beggar is arrested and locked up at the police station, and Holmes initially is quite convinced that Mr. St. Clair has been the unfortunate victim of murder. However, several days after Mr. St. Clair's disappearance, his wife receives a letter in his own writing. The arrival of this letter forces Holmes to reconsider his conclusions, leading him eventually to an extraordinary solution. Taking a bath sponge to the police station in a Gladstone bag, Holmes washes Boone's still-dirty face, causing his face to be revealed — the face of Neville St. Clair! Upon Mr. St. Clair's immediate confession, this solves the mystery, and also creates a few problems. It seems that Mr. St. Clair has been leading a double life, one of respectability, and the other as a beggar. In his youth, he had been an actor before becoming a newspaper reporter. In order to research an article, he had disguised himself as a beggar for a short time, during which he earned a very large amount of money. Later in his life, he returned to the street to beg for several days in order to pay a large debt. Given a choice between his newspaper salary and his high beggar earnings, he eventually became a professional beggar. His takings were large enough that he was able to establish himself as a country gentleman, marry well, and begin a respectable family. His wife never knew what he did for a living, and Holmes agrees to preserve Mr. St. Clair's secret as long as no more is heard of Hugh Boone.