David Ulansey's book breaks new scholastic ground by arguing that the Roman cult of Mithras did not originate in Persia, as previously thought. Instead, Ulansey suggests, the cult was triggered by the reaction of a group of Tarsian intellectuals to the discovery in 128 BCE, of the Precession of the Spheres. To these fatalistic Stoics the only possible explanation for this phenomenon was the existence of a divinity powerful enough to shift the heavens, and this was to become the revelation at the heart of the Mithraic mysteries. This information was then married to the astrology of the zodiac and to the symbolism of popular Tarsian myths surrounding Perseus to create the fabric of the religion. David Ulansey's study is an absorbing, carefully researched, and frequently beautiful description of an ancient cult which long fascinated scholars by virtue of the lack of written evidence concerning it and the paradoxical wealth of artefacts and iconography uncovered by archaeologists.