The evil Muns tries to convert Abby into helping him change the history of the world while her and Derick's grandfather asks Derick to finish a challenge that a trusted teacher was never able finish.
Derick and Abby Cragbridge continue their seventh-grade year at Cragbridge Hall, where they enter competitions, meet new friends, run into virtual zombies, and real danger.
When twins Abby and Derick start at Cragbridge Hall, the school their grandfather founded, they discover firsthand the dangers of time travel and must find a way to save their parents, who have been s
