The Summoning by Kelley Armstrong

Aspiring film director Chloe Saunders is an average fifteen-year-old girl – pretty, but not too popular – with a wild imagination. When she suddenly begins dreaming about ghosts, Chloe brushes it off. But the day she is accosted by the charred ghost of a school custodian and runs screaming through her school’s halls, she is shipped to a group home for the mentally unstable. Chloe is diagnosed with schizophrenia, but as she gets to know the other students at the home, she begins to wonder whether there are other, darker, powers at play. The mystery of how and why each student has ended up at the home, and whether Chloe is really crazy after all, consume her. This sets off a chain of events that ripples through the rest of Armstrong’s Darkest Powers trilogy.