During the year 1866, ships of various nationalities sight a mysterious sea monster, which, it is later suggested, might be a gigantic narwhal. The U.S. government assembles an expedition in New York City to find and destroy the monster. Professor Pierre Aronnax, a French marine biologist and the story's narrator, is in town at the time and receives a last-minute invitation to join the expedition; he accepts. Canadian whaler and master harpooner Ned Land and Aronnax's faithful manservant Conseil are also among the participants. 

The expedition leaves Manhattan's 34th St. Pier aboard the U.S. Navy frigate Abraham Lincoln, then travels south around Cape Horn into the Pacific Ocean.  After a five-month search ending off Japan, the frigate locates and  attacks the monster, which damages the ship's rudder. The three  protagonists are hurled into the sea and ultimately climb onto the  monster itself, which they are startled to find is a futuristic  submarine. They wait on the deck of the vessel until morning, when  they're captured, hauled inside, and introduced to the submarine's  mysterious manufacturer and commander, Captain Nemo.