Overview
The Six Messiahs is a 1995 novel by Mark Frost, a sequel to his 1993 novel The List of Seven. The two main characters are real-life person Arthur Conan Doyle (albeit engaging in fictional actions) and fictional character Jack Sparks.
Summary
The year is 1894, and Arthur Conan Doyle is visiting America on a book tour with his brother, Innes Doyle. He is also secretly investigating the disappearance of a number of holy books, on the orders of Lord Gladstone. En route to New York City, there is a mysterious murder of a rare book dealer aboard their steamer. Even more shocking, an elderly priest traveling with them reveals himself as a disguised Jack Sparks, who survived his fall over the Reichenbach Falls but has become a broken man (physically and spiritually).
Jack has been experiencing a series of dreams about a "black tower" in the middle of a desert, which has drawn him to America. Identical dreams have also been experienced by four other diverse individuals, some of whom are also investigating the recent thefts of holy books. These include:
Kanazuchi: a Buddhist monk from Japan and a deadly warrior, who travels to San Francisco from Japan and learns that a holy text stolen from his monastery was taken east from California;
Walks Alone, aka Mary Williams: a Native American woman following her dreams west, toward Utah;
Rabbi Jacob Stern: an elderly Talmudic scholar from Chicago and expert on Kabbalah;
Peregrine "Presto" Raipur: an Indian prince and amateur magician;
Also included in the mix are: Eileen Temple, English actress and Doyle's former lover, traveling west with her second-rate theatre troupe; and Dante Scruggs, a serial killer recruited by the book thieves.
From Wikipedia (CC BY-SA 4.0).