When a mysterious sea creature threatens international shipping, Professor Pierre Aronnax joins an expedition that leads him into the captivity of the enigmatic Captain Nemo. Professor Aronnax, his loyal servant Conseil, and the harpooner Ned Land find themselves aboard the Nautilus, a technologically advanced submarine operating beyond the reach of conventional governments. As they traverse the world's oceans, Aronnax must balance his scientific curiosity regarding the underwater environment with the moral dilemma posed by Nemo's violent crusade against civilization. The narrative is presented through the journals of Aronnax, providing a detailed, first-person account of their observations and the psychological tension within the vessel.

Readers frequently highlight the balance between Verne's meticulous scientific detail and the sense of wonder evoked by the underwater setting. Discussion often centers on the complex characterization of Captain Nemo, whose motivations remain a subject of debate among scholars and casual readers alike. Critics often note the pacing, which shifts between long passages of descriptive cataloging and moments of high-stakes tension. The work is widely recognized for its influence on the development of science fiction as a genre, particularly regarding the depiction of futuristic technology. Many readers appreciate how the narrative manages to remain engaging despite the heavy emphasis on technical and naturalistic observation.