Aisling, a goddess in human form, was born to rule both domains and --- with her twin, Anya --- unite the Celts with the powerful faeries of the Middle Kingdom. But within medieval Ireland, interests are divided and greater forces are mustering. Both England and Rome have a stake in driving magic from the Emerald Isle. Jordan, the Vatican commander, is tasked with vanquishing the remnants of otherworldly creatures from a disenchanted Europe. However, he finds himself torn between duty and his desire to understand the magic that has been forbidden.