Signs of Civilization (Terra Quest 1-5)

Synopsis
With the help of climbing equipment, Summerle and Dull Echo began to descend. It turned out that the appearance of the crater was decisive: after a few meters its diameter began to increase.

Completion
As soon as they reached the bottom Summerle started looking around using her flashlight. 'Look at the walls of the crater, Echo! These are petroglyphs!'