It's Wysteria Belles' last day at East Vanhoover High. To commemorate their friendship, Wysteria and her classmates take a field trip to the Canterlot Royal Museum. Before entering the building, Wysteria's friend Mercy has them try a charm she found in a book that will allow them to stay best friends forever. Everything seemingly goes well after the friends complete the charm, however, things quickly go sour when an earthquake sends them plunging into what they will soon know as hell and a race to escape with their lives (and sanity) intact. And what they'll uncover while they're there just might change their lives, and not for the better.