The crew of Starship Hummingbird are doing everything they can to make contact with the unidentified flying object. Will they be successful?

Now things are getting serious: The crew is getting ready to launch, and the two young pilots are eager to go along for the ride. Will they be able to persuade their fathers to let them?

The new recruits of the Milky Way security force arrive for training. Pierrette is worried about Fat Nose's threatening behavior. Meanwhile, the UFO enters the ship's observation space. This calls for immediate action!

The representatives of the confederation, chaired by the President, are now to vote on how to deal with the unknown flying object. There is no consensus at all!

An unknown flying object appears on the radar. Pierre, Pierrette, and Maestro discuss where it might come from and whether it might be hostile.

Heidi now learns the entire story from her grandfather about her father’s devastating accident. She comforts him, and promises that she will always stay with him.

Heidi runs to her grandfather in tears because she can't believe what people are saying about him. Is he really to blame for the death of Tobias, Heidi's father?

Heidi and Peter manage to trick Karl and Theresa into telling them where Peter’s treasure chest is hidden. They bring the chest back to the tree house. But someone has been spying on them!

The treasure hunt can begin! The two teams have been given different clues by Karl, and are now setting out on the adventure.

When Peter plans to climb a mountain to harvest snail clover, he leaves Heidi behind to look after the goats. But things don’t exactly go as planned…

Peter and Heidi are shocked to see that Karl, Theresa, and Willi have taken over their tree house. But then Heidi hatches a plan to get them out…

Heidi and Josef comes across what appears to be a little dog caught in a trap, and try to help it. But the townspeople are certain that there are hungry wolves roaming the area…

Leipzig, 1989: Twelve-year-old Fritzi lovingly looks after a little dog belonging to her best friend, Sophie, who has apparently gone on summer vacation with her family in Hungary. But when Sophie doesn’t return in the fall, it becomes clear that her family actually fled to West Germany. Fritzi courageously sets out to return Sputnik to Sophie… and gets caught up in a movement that’s changing the future of the country.

Heidi and her grandfather ride a sled through the valley — it’s her first time, and she loves it! Peter, meanwhile, is having a rough time in class, and the teacher isn’t going easy on any of the students today.

Karl discovers that a fossil has been taken from his collection. He accuses Heidi and Peter—but the culprit turns out to be someone else.