What should an aristocrat do if he is concerned about his cousin's strange behavior, in particular his habit of constantly wearing gloves? Or a schoolteacher whose lighthouse keepers brothers mysteriously disappeared? Or the British intelligence service, which needs a brilliant chief in order not to be defeated in the world war? Or even Winston Churchill himself, the Home Secretary who was challenged by the anarchist international? Of course, all of them can be told with absolute certainty: the shortest path to solving the problem leads through house 221 on Baker Street, where the notorious Mr. Sherlock Holmes and Dr. Watson live.