Answer:
When Harry regained memory again he was very weak because he had been lost for four days,.The next morning he woke up, and he heard something, They were the waves and the wind. Harry thought it was a hallucination.
The next day, when he could open his eyes, he did not believe that the ocean was in front of him with a deeply indented shore lined with a breadth of fine shining sand, softly lapped by the waves.
Harry thought of the theory of an English captain, who likened the earth to a vast hollow sphere, in the interior of which the air became luminous because of the vast pressure that weighed upon it .
Finally he realized they were the only living creatures in this subterranean world.
Step-by-step explanation:
Not sure if the other guy answered your question so uhh yeah.. (btw Alex/Axel? was replaced with Harry in my assignment in case not many people know this)