Surgical and trauma nurse Harlow Frye loves the small town of Knightly, where breathtaking views of the Sierra and a tight circle of female friends provides a refuge from her professional life. But lately, it's Harlow's personal life that's causing all the chaos. First a series of anonymous threatening letters are left in her mailbox. Then, Harlow is dealt a blow when her friend Lawyer dies after reacting to some sort of toxin. And to top it off, Harlow finds her secret obsession, CIA operative Hawk Wilder, bleeding out on a mountain trail. As Harlow turns her home into a makeshift hospital, her infuriating, attractive patient insists on distracting her. But even in the face of their increasing connection, there's no way Harlow can ignore the escalating storm when someone else close to her is struck down by the mysterious toxin. With little more than intuition to go on, Harlow turns to the five friends who have proved themselves to be a better family than her own flesh and blood. As the women attempt to unravel the killings, they will need to rely on their instincts and their connection to each other-or else they'll lose everything they've come to hold dear.