Full moons bring out the dangers, and for private investigator Sam Hain, that means a supernatural creature has run afoul of the Veil Watchers, a government organization dedicated to preventing humans from knowing they share a world with supernatural creatures by any means necessary. As her birthday nears, an evasive redcap asks seeks her aid for a banshee whom a young woman filmed singing her warning of doom and then uploaded the video to social media. As the video went viral, teams of amateur ghost hunters descended upon the sleepy Irish village of Bannagh. Now the banshee, the young woman who discovered her, and numerous ghost hunters are in danger from the Veil Watchers and from ancient evils and shadowy forces alluded to in the banshee's song. With only four days before Veil Watcher Michael Cormack arrives to preserve the secret through a shoot-first policy, Sam has little time for error if she is to protect everyone from overzealous Watcher Michael Cormack, known for his scorched earth approach to keeping the secret safe. And as ancient evils rise and threaten the living, Sam's resolve to protect the lives of all involved will be tested as she unravels the mystery of Liam's doom.