Joining the Alliance might be the key to seeing the worlds she's always dreamed of, but Ada's new job causes a rift to form between her and her guardian, Nell. As she struggles to come to terms with the events of the previous month, Ada is reluctant to use magic again after the damage it caused. Kay, meanwhile, faces his first challenge as one of the Alliance’s offworld Ambassadors - helping his colleague, Markos, investigate the mysterious death of the centaurs’ king back on his homeworld of Aglaia. When they realise magic is involved, Ada is pulled into the investigation. But tensions between humans and centaurs run high, and avoiding a bloodbath will be more difficult than any of them expect. Especially when Kay discovers something about his own magic that could affect the future of the Alliance. Against an enemy they quite literally can’t see, Ada and Kay must face up to the power that almost destroyed their lives…