While Coconut, Oskar, and Matilda are playing on the beach, they notice that the Gugelhupf, the volcano of Dragon Island, is spewing more ash and rocks than usual. Luckily, the alien volcanologist Dotti from the planet Oxi is visiting again and explains to the friends how a volcanic eruption occurs and what happens during it. What is the difference between magma and lava? How hot does it get in a volcano? Are there underwater volcanoes? The three friends learn a lot of interesting facts that they can share with all Coconut fans.