Grandma Bine and her two grandchildren are searching for the Mysterious Island, which, according to legend, becomes visible only under certain weather conditions: when it rains, when it snows, and when the sun shines.
The Red Caps patrol adventures in each episode in a different country. The patrol focuses on helping children and solving their problems. Opposed by the patrol is Santa's twin brother Basil and his assistant. In practice, the Red Caps Scout and Basil compete on which side manages to find the pieces of the magic crystal before the other and reassemble the crystal. Unless particles of the crystal are found before the Christmas Star lights up, Santa will not be able to distribute gifts to the children of the world.
