It's thousands of years in the future. The sun has expanded and the surface is unhabitable, so humanity now lives deep within the ocean. A scientist family gets information from a space probe of a viable planet, like Earth, and they prepare to go to the surface. But they are stopped by pirates. The father is killed and the two young children are kidnapped. Then, the story picks up a decade later, with the mother and her remaining son. She still wants to tell people about the planet, the son is a sort of corrupt cop, and they eventually, through a series of mishaps, are reunited with that same pirate and meet the kidnapped sister, who has changed quite a bit into someone who is not so friendly. This is an engrossing story with beautiful art but it's very depressing. Recommended is you're in an apocalyptic mood.