"For some moments distant Vesuvius had beguiled my thoughts from the still more distant mountain of the secret, when suddenly a white girl in a white hood and a long white cloak passed me on the white deck: whereupon I forgot mountains of reality and dreams. She was one of those tall, slim, long-limbed, dryad-sort of girls they are running up nowadays in England and America with much success."
Lord Ernest Borrow and Captain Anthony Fenton think they know a secret - a secret that could make them both rich - but they are interrupted on their quest between Naples and Alexandria by Sir Marcus Antonius Lark, by a woman who thinks she is the reincarnation of Cleopatra, an American Heiress, and Mrs. Jones, a mysterious Irish woman with a past. Will they ever find the secret? Or will their adventure lead them to another discovery altogether?