In Sherlock Holmes’s story “The Adventure of the Empty House,” Colonel Moran uses an air rifle to shoot at Holmes.
The story reveals that Professor Moriarty was not the only major criminal threatening Holmes. Colonel Sebastian Moran, a former army officer and expert big-game hunter, has become one of London’s most dangerous criminals. He uses a specially constructed air rifle to fire a revolver bullet silently and accurately from a distance.
Holmes anticipates Moran’s attack by placing a wax bust of himself in the sitting room of an empty house opposite 221B Baker Street. The bust is moved repeatedly so that it appears to be Holmes visible through the window. Moran fires at the decoy, and Holmes and Watson then surprise him.
The air rifle is important because it allows Moran to imitate a long-range assassination without the obvious sound of a conventional firearm. The story’s weapon is sometimes loosely called a gun, but Doyle specifically presents it as a specially designed air rifle. “The Adventure of the Empty House” also marks Holmes’s return after his supposed death at Reichenbach Falls.