NATIONAL BESTSELLER - Six years after their cousin vanished from their home while they were sleeping, two sisters set out to learn the truth behind what happened--even if it puts their own lives in danger--in this haunting thriller from the internationally bestselling author of What's Done in Darkness. "Beautifully written, unflinchingly told, and relentlessly suspenseful."--Heather Gudenkauf, author of The Overnight Guest...