After winning the competition, Conny’s class will be allowed to spend the night in a museum! Conny and Billy are thrilled at the idea of wandering through dark halls with a flashlight and sleeping in a cave of a primitive man. But Anna is worried: what if the mummies come alive in the museum at night? When the museum lights are turned off, the atmosphere becomes a bit scary. Hearing strange sounds, the girls decide to find out what’s going on. Maybe Anna’s fears aren’t in vain.