A talking May beetle called Sumsemann enters the window of children Anneliese and Peterchen who laments the loss of his sixth leg on the moon. The kids promise to help retrieve the leg - which is guarded by the nefarious Man in the Moon.
Anneliese and Peterchen receive the ability to fly - but only until dawn. If they take too long, they are trapped on the moon forever. The kids and the May beetle start their dangerous flight and immediately enter a fierce storm.
Anneliese and Peterchen encounter the Sandman who is stuck with his sled. With the help of the sky goats the children manage to release the vehicle. After they rescue a little butterfly, they journey to the castle of the Night Fairy.
The group rides Ursa Major to the moon. When a comet sets Ursa Major's tail on fire, the children are tasked to extinguish it. When they finally reach their destination they start to look for food for the Great Bear.
Having reached the moon, the group encounters the Easter Bunny, much to their surprise. They then continue the journey on Ursa Major's back, encounter greedy moon wolves and finally face the dangerous Man in the Moon himself.