When Rudi spots a treasure chest nestling in a forest far below him he flies towards it at top speed which is a bit too fast for Trudi and both of them crash land. When they take a closer look at the treasure chest they realise that it has no key. Rudi is determined to open it and manages to hack open the lock with his beak. When they open the chest however, it is empty apart from one tiny seed. Rudi decides to gobble up the seed but realises immediately that it’s not edible!
The pair decide to plant it instead and see what happens. Trudi thinks it might be magic. The pair are just about to leave, as nothing was happening, when suddenly the seed grows in to an enormous tree. They decide to see where it leads to and while climbing it they discover that the tree is magic and can talk.
Right at the top, the pair find themselves in a land of giants and meet a friendly giant called Prince Ludo. Sadly his brother Prince Gristle is not so friendly and would like nothing better than to gobble up Rudi and Trudi if he could only find them. His keen sense of smell tells him that there are some "live-uns" about and they are his favourite food. Ludo tells Rudi and Trudi that if Gristle becomes king he will undoubtedly invade the "live-uns" world. It transpires that the two giant princes are locked in a battle to make "old wise beard" laugh and the winner will become king. Old wise beard has not laughed for a very long time. Trudi and Rudi decide that Ludo must become king so as to stop Gristle from being crowned and they set about trying to make Ludo funny. After one failed attempt with a custard pie Trudi comes up with a plan. The next time Ludo is trying out his routine in front of Wise Beard, Rudi and Trudi crawl inside his clothes and tickle him. Wise Beard thinks that some sort of clever magic on Ludo's part has made him laugh. He is delighted and happily crowns Ludo king. Happy in the knowledge that the land of the "live-uns" is now safeguarded, Rudi and Trudi climb down the tree. The tree is so tired after hearing all about the adventure that it turns back in to a seed so that it can go back in to the treasure chest for a rest.