The Templar Legacy — Steve Berry

Onetime U.S. operative Cotton Malone teams up with his former supervisor, Stephanie Nelle, to find the legendary cache of wealth and forbidden knowledge thought to have been lost forever when the Knights Templar were exterminated in the fourteenth century. Nelle is armed with vital clues to a series of centuries-old puzzles scattered across Europe, but also in pursuit of the historic prize is a shadowy zealot with an army of assassins at his command. At the end of the trail lies a discovery that could rock the civilized world--and, in the wrong hands, bring it to its knees.