A month after the demon attack, Jentry and Ed steal away to Diyu on important family business. But nothing there is quite as it seems.

Armed with her mother's memories, Jentry tries to make up for lost time. Meanwhile, the students prepare for a Lock-In at school.

Tensions hit a boiling point within the walls of Riverfork High when demons crash the party, forcing Jentry and her friends to fight for their lives.