These essays, which appeared, with two exceptions, in 'The Cornhill Magazine, ' have been revised, and some alterations, corrections and additions have been made in them. Contents: Case of Elizabeth Canning; Murder of Escovedo; Campden Mystery; Case of Allan Breck; Cardinal's Necklace; Mystery of Kaspar Hauser, the Child of Europe; Gowrie Conspiracy; Strange Case of Daniel Dunglas Home; Case of Captain Green; Queen Oglethorope; Chevalier d'Eon; Saint Germain the Deathless; Mystery of the Kirks; End of Jeanne de la Motte.