James Rollins

From the #1 New York Times bestselling master of international intrigue comes a shocking new stand-alone thriller that thrusts a group of university students, falsely accused of murder, into a treacherous hunt across Europe, all to unlock the secrets buried within a centuries-old book that could change humankind forever. Knowledge can be magic-until it falls into the wrong hands. The ritualistic murder of a British professor at the University of Exeter points to a startling cast of suspects: his own students. All are enrolled in a postgraduate program covering the history of witchcraft, folklore, and spiritualism.
All evidence points to Sharyn Karr-an American student. Prior to the professor's death, he had thrust a centuries-old book upon her. It appears to be the handwritten and encrypted diary of an eighteenth-century mystic and occultist, the Comte de Saint-Germain. The professor begged her to keep the text safe, ending with a warning. Trust no one.  Such a responsibility forces her into cooperation with Duncan Maxwell, a fellow postgrad and the sixteenth in line to the British Crown.
Already, Duncan has proven himself a savant with encryptions. Unfortunately, the pair clash at every level, but they both need one another. Especially when they discover the book's opening words:  Herein lies the secret to my immortality. Come find me, if you dare. As dark forces close upon the pair, she and her friends are forced to flee, pursued by law enforcement and hunted by a powerful cabal.
In an explosive chase across Europe-from the Tower of London to Parisian chateaus to a fortress in the Italian Alps-Sharyn must learn the true secret hidden in Saint-Germain's text. It will send her and the others across history and deep into the heart of one of the world's greatest mysteries, a secret buried at the roots of Western Civilization, a discovery that could topple empires and change humanity forever.
For what lies at the end of Saint-Germain's diary is as shocking as its opening words.