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
20,000 Leagues Under the Sea (1954 film) come to pass, in God's good time". In 1950 Sig Rogell announced he had bought the rights to the novel as well as to an adaptation prepared by Robert L. Lippert's production company. He was going to make the film independently. The rights eventually went to Disney. "20,000 Leagues Under the Sea" was filmed at various locations in The Bahamas and Jamaica, with the cave scenes filmed beneath what is now the Xtabi Resort on the cliffs of Negril. Filming began in spring of 1954. Some of the location filming sequences were so complex that they required a technical crew