Summary

Chapter 20 – Axel realizes there are enough provisions for only three more days as they continue on in their journey. The earth around them reveals Devonian fish and reptile fossils and debris. As they travel on, they discover they have moved into a massive coal vein. They enter a massive cavern, where all the ages of the coal period of history can be seen. Axel notes that all the coal in the world will be exhausted by excessive consumption within three centuries if not recognized by the industrial world. At last, they arrive at a dead end –and must turn around and go back to the other tunnel. However, they have only one day’s worth of water, left.

Chapter 21 – It will take Axel, Otto, and Hans five days to return to the crossroads passage. On Tuesday, July 7th, they return, exhausted, to the passage...