Kendall, almost thirteen, faces such middle-school issues as the mysteries of quadratic equations and her first boyfriend, Brandon, and also the ghosts who need her help to cross over, including Danielle the gymnast and Mrs. Dunham, Brandon's mother.
With help from her best friend Ava and Ava's boyfriend Noah, Hannah is recovering from being dumped by her boyfriend Sebastian, but on the first day of their senior year in high school, Ava learns that Hannah and Noah betrayed her while she was away.