The scientific research submarine "Comma" is a keen fan of the science fiction novel "Journey to the Center of the Earth". He followed his uncle, geologist "Iron Stone", to examine mysterious substances on the sea bed. , accidentally pulled into a cave labyrinth to dive deep into the Mariana Trench and embark on an unimaginable underwater exploration at the center of the earth, heading into the huge unknown world..—Journey to the Center of the World