A fascinating journey through time and across Europe and Central Asia, in search of the prophet Zarathustra (a.k.a. Zoroaster)-perhaps the greatest religious lawgiver of the ancient world-and his vast influence. In Persia more than three thousand years ago, Zarathustra spoke of a single universal god, the battle between good and evil, the devil, heaven and hell, and an eventual end to the world-foreshadowing the core beliefs of Judaism, Christianity,...