Shelby Black has spent the past six months training to be an exorcist. Her great-uncle Roy - a Catholic priest - has put her through exorcist boot camp hell, hoping to develop her talent, but ohmygod, he still doesn't trust her to do an exorcism on her own. High school is hard enough without having to explain that you fight demons for a living, so Shelby keeps her extracurricular activity to herself. The last thing she wants is for her crush, Spencer, to find out what she does in her off time. But Shelby knows how to keep a secret - even a big one. Like the fact that her mum left under mysterious circumstances and it's all her fault. Shelby is hellbent on finding her mum, no matter what it costs her - even if what it ends up costing her is her soul AND a relationship with Spencer.