After the death of her father when she was a child, Kit Gordy has grown up as a troubled teen for disgust of her mother Ginny and her stepfather Dave Dabrowski. Called to the principal's office of her high school and accused of a failed attempt to burn it, Kit is expelled from the high school, but Dr. Heather Sinclair, member of the staff of the Blackwood Boarding School, appears to offer her a place in the next school year. Ginny enlists Kit against her will in a try to correct her daughter, and Kit travels Blackwood, an old, isolated and dark mansion in the middle of a forest outside the city. There she meets her companions: nice Izzy, shy Ashley, reluctant Sierra and borderline Veronica, so troubled teens as her own. In the dinner presentation, Kit and the other girls meet Madame Duret, Blackwood's headmistress, and the rest of the staff: Pr. Farley (maths), Jules Duret (music), Heather Sinclair (arts) and Mrs. Olonsky, Madame Duret's rude right-hand to keep the peace in Blackwood. Locked in a place without internet, cell phones and all trace of modern technology, Kit watches as all change in a weird way: Izzy develops an extreme obsession for mathematics, Sierra for painting, Ashley for writing and herself for piano, meanwhile that Veronica keeps out from this obsession. Trapped between her love interest for Jules, Madame Duret's son, and strange memory losses, Kit asks help Veronica to discover the reason of their different changes. Investigating the ruined and forbidden wing of Blackwood at the same time that the works of Izzy, Ashley, Sierra and the own Kit, this last one and Veronica realize not only that all them have one secret in common, but the previous students suffered a horrible fate caused by the Blackwood's supernatural forces, that it will be too their own unless they find a way to avoid it.