It's history week at Pleasant Valley Elementary. Mr. Peabody has organized some very cool AND educational events. But Leo and Tia haven't seen him since he vanished into a weird portal, along with the villainous McSticky. When Mr. Peabody suddenly reappears, he comes bearing bad news: McSticky, has a dangerous space-time ray and he's not afraid to use it... to change the course of history! Will the Lunch Club gang be able to stop him in time?

Translation of: La momie spatio-temporelle.