In the story, the backdrop is a cosmic battle between angels and God, instigated by Lucifer's rebellion. When some angels choose not to take sides, preferring love over allegiance, they are cast out and become known as the Fallen. We are introduced to Lucinda Price, who is en route to Sword and Cross Academy, unaware of the supernatural elements that lie ahead. Her troubled past has landed her at this academy for delinquents, which caters to students struggling in traditional academic environments, including those with mental health issues and societal troublemakers.