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 an extensive bibliography, appendices and a wide-ranging introduction studying the novel from a literary perspective. In particular, his original research on the two manuscripts studies the radical changes to the plot and to the character of Nemo forced on Verne by the first publisher, Jules Hetzel. The national origin of Captain Nemo was changed in most movie realizations; in nearly all picture-based works following the book Nemo was made into a European. However, he was represented as an Indian by Omar Sharif in the 1973 European miniseries "The Mysterious Island". Nemo is also depicted as Indian in a silent film