A New York Times bestseller from author, Michael J. Sullivan, comes a tale of unlikely heroes who must rise to the call when history knocks, demanding to be let in. After years of warfare, humanity has gained the upper hand and has pushed the Fhrey to the edge of their homeland, but no farther. Now comes the pivotal moment. Persephone’s plan to use the stalemate to seek peace is destroyed by an unexpected betrayal that threatens to hand victory to the Fhrey and leaves a dear friend in peril. Her only hope lies in the legend of a witch, a forgotten song, and a simple garden door.