Legend has it that in the depths of the ocean, there is a mysterious civilization and race, they are brilliant and powerful. However, it has only kept a few words about them in history, without any record. Some scholars said that they are most likely to cause genocide because of the changes in the marine environment … Some scholars also said that there is an unimaginable great terror in the depths of the ocean and they have been destroyed by this terrorist existence … In short, different opinions, no one can take any evidence to prove their own. With the rapid development of science and technology, finally, an expedition decided to dive into the deep sea to explore this lost civilization.