A 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, and Islam....