원문 언어: 영어
This underground world is lit by electrically charged gas at the ceiling, and is filled with a very deep subterranean ocean, surrounded by a rocky coastline covered in petrified trees and giant mushrooms.Whilst on the water, they see several prehistoric creatures and are nearly eaten by an ichthyosaur, which fights and kills a plesiosaur.This part of the coast, Axel discovers, is alive with prehistoric plant and animal life forms, including giant insects and a herd of mastodons.