The king of a great empire cannot decide which of his three sons he should appoint as heir to the throne. In his desperation, he finally blows three feathers into the air and instructs his sons to follow one of the feathers each and bring a carpet from where the feather falls. But whoever would bring the most beautiful carpet was to be king in the future. The two older brothers set off confident of victory. But the third, who is considered the stupidest by everyone, seems to be unlucky, because the feather falls directly to the ground in the garden. But then the young man, Doc Croc and Yoyo discover a mysterious trapdoor that leads into an underground cave.
