Arthur Conan Doyle's account of the Oscar Slater case begins as a passionate protest against a grave miscarriage of justice. He reconstructs the murder of Miss Marion Gilchrist, a wealthy, reclusive Glasgow woman found savagely beaten in her flat after her servant, Helen Lambie, left her alone for only a few minutes on December 21, 1908. Neighbors heard a thud and three knocks, then saw a well-dressed stranger leaving the building, but the scene was oddly inconsistent with robbery: valuables remained untouched, only a single brooch was missing, and the killer's route seemed uncertain. Doyle then dismantles the prosecution's case, exposing shifting eyewitness descriptions, contradictory identifications, and the dangers of suggestion and prejudice. The evidence against Slater—his pawning of a brooch, his travel under aliases, a small hammer in his luggage, and his departure from Glasgow—proves increasingly fragile, especially once the brooch is shown to be his own property and his emigration plans are revealed to have been known in advance. Against a trial built on unreliable testimony and factual misstatements, Doyle argues that Slater's conviction could not stand. This edition has been fully restored with modern typesetting, custom cover design.