… We ran as mad for thirty minutes. Suddenly, the ground under our feet disappeared. We have fallen into a tunnel and were falling deeper and deeper for one hour. As it was very hot and the air was thin and damp we thought that we were somewhere very close to the middle of the earth. But in the next moment we felt on a cold rock. We were so surprised that we needed some minutes to get our breath back. After that we looked around and recognized that we were really in the middle of the earth. We were so happy about it, but we didn’t forget the proximity of the danger. After some moments we found a big red button and we realized that all we have to do is to press it. …