Nadia: The Secret of Blue Water

The Valley of Dinicthys (1x14)

Air date: Jul 20, 1990

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....