20,000 Leagues under the Sea

Verne's 1869 novel remains one of science fiction's founding achievements, and it earned that status honestly. The journey aboard the Nautilus through the world's oceans — hunting grounds, coral graveyards, underwater cities, a giant squid attack — is extraordinary imaginative world-building that was also uncannily predictive of real submarine and electric technology. Captain Nemo is one of literature's great complex antiheroes: romantic, principled, and capable of real violence in the name of his revolution against colonial powers. The significant caveat for modern readers is translation quality — this novel exists in English in dozens of versions of wildly varying fidelity and readability, and the edition in hand matters more than usual. Extended taxonomic catalogues of sea creatures slow the narrative. Mature middle-grade and up. Faith-neutral.