Sylvia is done with serial killers, done with therapy, and done with a New York City now rife with WHISPs—the creepy, grey shadows of her nightmares. She and husband Ben have a deal. She retires and they both move to Montana to escape the WHISP phenomenon. It is the only way to save their marriage after the Chester case, even if it leaves their WHISP-affected son, Lincoln, behind.

Then the phone rings. Chester’s in jail, yet there’s been a copycat murder, and Sylvia can’t let the case go. If she missed something the first time, this new blood is on her hands. Ben gives her a month to work the case, but can their marriage survive that long? And as Sylvia digs deeper into the depths of the source of her phobia, how long will her sanity survive?