Ella, Astrid, and Sydney were planning the perfect summer after high school graduation. But when Astrid commits suicide in a lonely cabin, the other girls' worlds are shattered. How could their best friend have done this--to herself and to them? They knew everything about Astrid. Shouldn't they have seen this coming? Couldn't they have saved her? As Ella hunts for the truth, and Sydney tries to dull the pain, a chilling Facebook message from Astrid...