Jean writes a song for Nadia. Actually, our pals burst out into song while various clips from the show play out.

After surviving a typhoon, Jean, Nadia, Marie, and King discover another island drifting mysteriously toward them. Exploring it, the children find Ayerton, a flaky scientist who they met on the battleship in Episode 3.

Jean, Nadia, Marie, and King are reunited with Grandis, Sanson, and Hanson. Together they all decide to live as a family on the new island, which Jean theorizes is moving.

With Grandis and her two accomplices, Sanson and Hanson, in pursuit, Jean takes Nadia back to his home in LeHarve. His grumpy aunt refuses to take Nadia in, but Jean lets Nadia stay at his own house. The following day, Jean and Nadia set off for Africa in one of his aeroplanes. They do not get far, however, when Jean's invention fails and falls into the sea....

A violent row between Sanson and Hanson turns into a race between two mechanical lions resembling King(!).

When King gets captured by Grandis' ex-fiancee, our pals set off to save him.

Imprisoned by the wicked Gargoyle, Nadia is forced to admit that she gave her Blue Water to Jean before turning herself in (to save Marie and King from a horrible fate). As the search for Jean is on, the boy desperately tries to find her. Simultaneously, Grandis, Sanson, and Hanson, who have also been imprisoned by the soldiers, break out of their prison cell and attempt to escape. While Gargoyle tours Nadia around his base, he showcases Neo-Atlantis's secret weapon, a tower known as Babel with the power to obliterate an entire island!

Marie and King run off to explore the island, when they find themselves both lost and pursued by Gargoyle's soldiers. Sanson comes to their rescue.

Marie and Nadia become sick from a dangerously fatal tropical fever. To save them from death, Nemo charts course for an underground reef, where he takes Jean, Sanson, and Hanson on a quest to find the cure. Coming back, however, they have to deal with a territorial, eel-like Dinicthys....

Nemo takes Jean and Nadia on a tour of his secret base, where he introduces the children to his closest friend, a talking whale named Irion, who hints at Nadia's responsibility to hold the Blue Water.

Jean, Nadia, Marie, and King are shipwrecked on a deserted island. They decide to make it their home for a while.

King gets jealous of Jean and Nadia becoming more intimate and runs away. Jean sets off to find him... but not before Nadia goes ballastic upon realizing that he does not remember the kiss she gave him (he had been stoned from the hallucinogetic mushrooms).

Having escaped their former island home, our pals crash-land into an African tribal village, where they are instantly captured... until one of its citizens recognizes Nadia.

The New Nautilus and Gargoyle, now aboard Red Noah, face off in a spectacular duel of pyrotechnics, lasers, and, ultimately, wills. Midway through, both crafts head into outer space. After finally breaking in, Nemo, Jean, and Electra confront Gargoyle, who now has Nadia under his control.

Jean, a 14-year-old orphan, sailing into Paris to help his uncle design an airplane for the Paris Exposition's flight competition meets a pretty young girl named Nadia and her pet lion cub, King. He ends up rescuing her from a woman named Grandis who is trying to get Nadia's jewel, the Blue Water. Nadia leaves the only home she ever knew - a circus - as Jean has offered to help her search for her place of origin, starting with the random choice of Africa...

Jean, Nadia, and King are shot down over a strange island where they find themselves outrunning a squadron of sinister masked soldiers. In their struggle to survive, they find an orphan girl, Marie, who lost her parents to the soldiers.

In a surprising turn of events, Grandis and her boys join forces with Jean to save Nadia, Marie, and King from Gargoyle. Their escape attempt nearly backfires, until the Nautilus shows up to save them....

Jean, Nadia, Marie, and King are taken aboard the Nautilus with their new enemies-turned allies, Grandis, Sanson, and Hanson. Technophiles Jean and Hanson are thrilled to be aboard the Nautilus. Grandis becomes dangerously smitten with Captain Nemo, much to Sanson's consternation. Nadia, meanwhile, is very suspicious about the submarine and its crew, particularly Nemo, who reacts with surprise upon seeing her for the first time....

Jean is tired of being treated like a child by the Nautilus crew. Hoping to cheer him up, Nadia suggests Jean to build another aircraft. Inspired, he sets off to do just that. At first he is determined to construct the new helicopter by himself, but then realizes he still needs the support of some grown-ups. With Hanson's help, Jean completes the craft and takes Nadia on a very delightful test flight. While airborne, Jean promises that he will one day take Nadia to Africa....

En route to Captain Nemo's home base of Antarctica, the Nautilus finds itself attacked by a territorial Nautilus shellfish.

Now that they are settled into their new island home (which they dub "Lincoln Island", Jean uses his knowledge and technology to bring a little civilization. Nadia, on the other hand, wants to live with nature... only to discover that doing so is a lot harder than she ever dreamed of.

As a result of Nadia's foolishness, the children only have meat for food. This infuriates Nadia so much that she declares to starve... until she becomes desperate to eat a can of rotten spinach, getting sick. Jean sets off to find a cure, only to become intoxicated by hallucinogetic mushrooms(!). Overwhelmingly grateful, and stupidly unaware that Jean is not himself, she gives him his first real kiss....

Four months afterward, the Gratan is nearly repaired, and soon our pals will set off for Africa. But first Jean and Nadia go off on a hike which leads them to a mysterious underground cavern that turns out to be more than they suspected. The exploration culminates when Nadia falls into a trance and vanishes behind a wall, leaving her clothes in Jean's arms! During all this, Ayerton tries to make his move on Grandis.

Finally, our pals arrive at Nadia's real homeland--Tartessos. As they tour through its long forgotten ruins, our heroine finally reveals her darkest secrets... including who she is. How will all this affect her relationships with everyone, especially Jean?

Gargoyle takes Nadia before the puppet leader of Neo-Atlantis, Emperor Neo, who reveals that he has a strong connection with both Nadia and Nemo. Eight time zones away, Nemo and the others plan to fight Gargoyle in a final duel. Throughout, both Jean and Nadia learn about the origins of the Atlanteans.