Of all the worlds in the multiverse, Adrathea is the last David Render would willingly revisit. What happened there broke his heart and drove him to retire from the UN Multiverse Survey. To hang up his sword, and leave the service of the Alvehn. But now Adrathea is in peril. An Alvehn device known as an empathy bridge - called the Gryphon Stone by the Adratheans - has been stolen. Without it, the centuries-old alliance between humans and gryphons is failing, and a bloody conflict looms. To prevent that war, the Gryphon Stone must be found and restored - quickly. However much it pains him, Adrathea is a world to which David's fate is bound by the most intimate of ties. He has no choice. Adrathea calls, and he must answer.