Sixteen-year-old Farris Aldan didn’t join the Sentinels to save the world.He joined to outrun his madness.In Obscura City, contracting the whisperis means shedding your skin and becoming a monster. As a newly trained Sentinel, Farris hunts the infected, hoping vengeance will silence the guilt over his best friend Calla’s death.Then he’s assigned his first solo mission. Track down Rena, a whisperis-infected punk rocker evading quarantine. From her black hair and beet-red eyes, she’s the spitting image of Calla. And Farris can’t bring himself to arrest her. Not with that face, not with that voice. Choosing Rena makes him a traitor. Now hunted by the Sentinels he idolized, including his adoptive father, Farris learns Rena’s connection to the whisperis runs deeper than anyone imagined. Visions of a cure guide her toward the Hollow, a hidden valley of darkness beyond the city. Only an ancient vantashade named Krieger knows the truth, but it offers a cure for a terrible her life. To save Rena, Farris must risk everything-his future, his family, even the cure itself. And it still might not be enough.