The story is loosely (very loosely) adapted from jules verne's novel Two Wan Li under the Sea, which means that they lift their favorite parts and then take them in a completely different direction. On the other hand, there are some challenging clues. They originally planned to stick to Verne's story more closely. See the "Lost Nadia" section below. ) The story is set in 1889, focusing on 14, a circus acrobat and an orphan with a mysterious past, Nadia. When a jewel thief appeared and stole the blue water, a jewel she owned might be a clue to her origin. She was rescued by Jean at the 1889 World Expo in Paris. Jean is an inventive genius of 14 years old, and his inventions are not always as successful as he planned. The two of them led the thief to chase, and finally landed in the Atlantic Ocean, where they were picked up by Captain N emo and Nautilus. As Nadia (and we) discover more about the blue water, who are the real bad guys, and why the fate of the whole planet ultimately depends on who owns the blue water, the series starts from there.

http://utd500.utdallas.edu/~hairston/nadiahpbck.html