Penny's abusive father is dead…but she still hears his voice in her head, encouraging her to hurt those around her. She can't go to school or be around her friends or even draw with a sharp pencil without her intrusive thoughts urging her toward violence. Desperate to get a handle on her OCD, she agrees to spend the summer at Camp Whitewood--an exclusive therapy retreat in the woods.

She feels optimistic when she arrives. The other girls all have their reasons for being there, which makes Penny feel a little less alone. But then she starts seeing things that can't possibly be there: the gold watch her father was buried with, his favorite whiskey spilled on her cabin floor...a terrifying figure she calls the Shadow Man looming at the foot of her bed. Penny thinks she is losing her mind, but when a girl goes missing, and is later found dead, it's clear that whatever is happening at Camp Whitewood isn't all in her head.

As the hallucinations become increasingly intense and more girls wind up dead, Penny must work with whoever is left standing to figure out what is real before the Shadow Man uses their traumas against them and claims their lives.
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