In the story, the police ask the brilliant consulting detective Sherlock Holmes to help in the investigation of a strange case. A single middle-aged woman named Susan Cushing receives a cardboard box in the mail. The box is found to contain two severed human ears. The police initially believe that Miss Cushing is simply the victim of a prank played by medical students and that the ears were cut off corpses. Holmes believes that the ears are evidence of a double murder and that Susan Cushing was not the intended recipient of the cardboard box.