When Peter sets out on a magical journey to rescue his little sister Anne, he needs to travel to mysterious territory: the Moon! Anne was kidnapped by the evil Moon Man when she tried to help the beetle Mr. Zoomzeman in search for his wife. On his fantastic adventure, Peter lands on the Star Meadow where he meets the sleepy Mr. Sandman. He knows, only at the Night Fairy’s dinner in the castle in the clouds, they can find out where Anne is – but there aren’t enough seats for everyone. So they join the wild race along the Milky Way against the five Spirits of Nature: Storm Giant, Lightning Witch, Henry Hail, Rainy Robin and Mother Frost…

The story of Little Peter and his sister Anneli, who help a May beetle named Mr. Zoomzeman (German: Herr Summsemann) to retrieve his missing sixth leg from the Moon. After a fantastic and dangerous overnight adventure they recover the leg and are returned to their beds at home.

After Sumsemann the beetle loses one of his arms to a troll, he invites brother and sister Peterchen and Annaliese to join him on a journey to the moon in a quest to retrieve his lost arm.