The Professor thinks he has found the way to the centre of the Earth. The Professor and Axel get Hans and return to the cave. Look, Hans - this is the cave! Let's see what's inside. Oh no! This huge rock is blocking the way. I have an idea. Let's use gunpowder to blow up that rock! The men leave the cave and Hans prepares the gunpowder... Be careful, Hans! Hans lights the gunpowder... Hurry! Let's take the raft out to a safe distance. A few minutes later, the gunpowder explodes. It worked! But something has gone wrong... Oh no! The explosion has caused an earthquake! We're going to die! A huge wave carries them inside the cave. Hold on, Axel! What's happening? The water is boiling hot. We must be inside a volcano, and we're going up quickly!