One of 12 stories in The Memoirs of Sherlock Holmes, first published in The Strand Magazine and Harper's Weekly in July 1893. Doyle ranked it 15th among his favorite Holmes tales.

Holmes visits Watson late one night to investigate the death of Colonel James Barclay of Aldershot Camp. Barclay's wife, Nancy, is suspected of murder. Despite Barclay's devotion to his wife, he had a vindictive streak, suffered from bouts of depression, and disliked being alone at night. Holmes digs deeper into the mysterious circumstances surrounding the case.