The story is based in 1866 where ships have gone missing and have been sunk by some unknown creature. This actually turns out to be the nautilus submarine. People go out to catch the creature and find their way into the nautilus submarines holding cells. They meet the captain of the ship Captain Nemo of the nautilus. He treats them well but asks that if asked, to go back to the cell. One of the captured, Pierre Aronnax is particularly interested in the library. And rights a diary of everything he see’s. they go on adventures and after an incident where the Captain sinks a ship the three of them escape and find their way to shore.
The name Nemo is a subtle allusion of Homers odyssey, which is a Greek poem where Odysseus says his name is Utis which translates as no-man/ no body. In latin as Nemo. Captain Nemo is depicted as a king of the underdogs and downtrodden.