The ocean is the most mysterious place on Earth. We probably know more about the other planets of the Solar system than about the depths of this vast expanse that covers 71% of the surface of our planet. Deep-sea exploration has been fascinating humankind since antiquity. In the “Alexander Romance” (earliest version traced to the third century BC), we find an episode in which Alexander explores the bottom of the sea in a glass diving bell. But the ultimate classic novel dealing with oceanic exploration is “Twenty Thousand Leagues Under the Sea” by Jules Verne (French: “Vingt mille lieues sous les mers”, 1870). This literary masterpiece is one of the earliest science fiction novels, and it features a particularly interesting postromantic character, the “tragic villain” Captain Nemo. Jules Verne shows us that the human soul is like the abyss; one can find light even in an ocean of darkness.