"It happens quietly one hot August morning in Iowa: two families awaken to find their little girls have gone missing in the night. Seven-year-old Calli Clark suffers from selective mutism brought on by a tragedy that happened when she was a toddler. Petra Gregory is Calli's best friend--and her voice. But neither girl has been heard from since they vanished. Now, Calli's and Petra's parents are tied by the question of what happened to their children. And the answer is trapped in the silence of unspoken family secrets."--Back cover.