Dark Waters (Once Upon a Time) is to take Snow's heart. The Land of Untold Stories is revealed to be the Mysterious Island from the book as the same name. The "Nautilus" is based on the submarine from "Twenty Thousand Leagues Under the Sea". Captain Nemo based on the protagonist from Jules Verne's novel "Twenty Thousand Leagues Under the Sea". Hook refers to the giant squid that attacks him as a kraken. The kraken is a legendary sea monster of giant size that is said to dwell off the coasts of Norway and Greenland. The episode posted its lowest numbers so far in the series, as
Twenty Thousand Leagues Under the Sea Ottoman rule during the Cretan Revolt of 1866–1869, proving to Arronax that he had not completely severed all relations with mankind outside the Nautilus after all. In another passage, Nemo takes pity on a poor Indian pearl diver who must do his diving without the sophisticated diving suit available to the submarine's crew, and who is doomed to die young due to the cumulative effect of diving on his lungs. Nemo approaches him underwater and gives him a whole pouch full of pearls, more than he could have acquired in years of his dangerous work. Nemo remarks that the diver