Fifteen years after stabbing a classmate to conjure up an imaginary ghost known as Mercy Black, Marina Hess returns home. She is being released from psychiatric care to live with her sister and her young nephew. But in the years after his crime, the myth of Mercy Black has gone viral, inspiring rumors, stories and even imitation crimes on the Internet. Marina is obsessed by what she has done and the ghost she imagined. Although he would prefer to leave the past buried, his nephew becomes increasingly obsessed with Mercy Black. To save him, Marina must confront her past and discover the truth behind Mercy Black. What she discovers is a very real and very deadly horror that will stop at nothing to claim her and her nephew.