20,000 Leagues Under the Sea by Jules Verne
During the year 1866, ships of several nations spot a mysterious sea monster, which some suggest to be a giant narwhal. The United States government assembles an expedition in New York City to find and destroy the monster. Professor Pierre Aronnax, a French marine biologist and narrator of the story, who happens to be in New York at the time, receives a last-minute invitation to join the expedition which he accepts. Canadian whaler and master harpoonist Ned Land and Aronnax’s faithful servant Conseil are also brought aboard.
The expedition departs Brooklyn aboard the United States Navy frigate Abraham Lincoln and travels south around Cape Horn into the Pacific Ocean. The ship finds the monster after a long search and then attacks the beast, which damages the ship’s rudder. The three protagonists are then hurled into the water and grasp hold of the “hide” of the creature, which they find, to their surprise, to be a submarine very far ahead of its era. They are quickly captured and brought inside the vessel, where they meet its enigmatic creator and commander, Captain Nemo.
The rest of the story follows the adventures of the protagonists aboard the creature—the submarine, the Nautilus—which was built in secrecy and now roams the seas free from any land-based government. Captain Nemo’s motivation is implied to be both a scientific thirst for knowledge and a desire for revenge on (and self-imposed exile from) civilization. Nemo explains that his submarine is electrically powered and can perform advanced marine biology research; he also tells his new passengers that although he appreciates conversing with such an expert as Aronnax, maintaining the secrecy of his existence requires never letting them leave. Aronnax and Conseil are enthralled by the undersea adventures, but Ned Land can only think of escape.