Frankie Rosenberg is the world's first slayer-witch, but she doesn't have that slay-life balance figured out just yet. She's still reeling from the deadly explosion at the annual slayer retreat, and new evidence that some slayers may have survived. While she's defeated her first Big Bad, Frankie soon realizes it was just a warm-up act. Bigger, badder forces of evil are just getting started. The Hellmouth has been reawakened and is calling old friends home.