Twins, Aimée and Juliette, are shocked by their parent's pronouncement, "We're sending you to boarding school." So unfair! Still, no amount of crying or pouting changes their sentence. Soon, they quit the quiet countryside of France for the Abbey, an uncommon school for girls with paranormal abilities. The uncommon becomes the unbelievable when a gyrating timeline-vortex hurls them back to the 1600s, to an outlandish abbey run by a mysterious sisterhood. Once there, the girls discover their own roommate is possessed by a ghost that's ruining her life. Never ones to dodge a mystery, the twins set out to solve Charlotte's haunting, forced to trek through the feared forbidden forest to seek help from an impulsive wizard. To avoid the Abbess and her rules, and a bevy of unforgettable characters, the girls must scheme and sneak around them all, creating a detective team of the highest order.