Since her father's death when she was a child, Kit Gordy has grown into a troubled teen to the 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, she is expelled, 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 an attempt to reform her daughter, and Kit travel to Blackwood, an isolated, dark old mansion in the middle of a forest outside the city. There she meets her companions: nice Izzy, shy Ashley, reluctant Sierra, and borderline Veronica, teens as troubled as herself. During dinner, Kit and the others meet Blackwood's headmistress, Madame Duret, and the rest of the staff: Professor Farley (math); Jules Duret (music); Heather Sinclair (arts); and Mrs. Olonsky, Madame Duret's rude right-hand peacekeeper. Locked in a place without Internet, cell phones, or any other trace of modern technology, Kit watches as everyone changes in strange ways: Izzy develops an extreme obsession for mathematics, Sierra for painting, Ashley for writing, and herself for piano; meanwhile, Veronica seems immune to obsession. Trapped between strange memory gaps and her love interest in Madame Duret's son Jules, Kit asks Veronica's to discover the reason for their different changes. They investigate the forbidden, ruined wing of Blackwood and discover that all of them--Izzy, Ashley, Sierra, Veronica, and Kit--have one secret in common, and that previous students suffered a horrible fate caused by Blackwood's supernatural forces, and it will be their fate as well unless they find a way to avoid it.