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 the protagonists' situation changes. No one seems to be on board any longer and the "Nautilus" moves about randomly. Ned Land is even more depressed, Conseil fears for Ned's life, and Aronnax, horrified at what Nemo had done to the ship, can no longer stand the situation either. One evening, Ned Land announces an opportunity to escape. Although Aronnax wants to leave Nemo, whom he now holds in horror, he still wishes to see him for the last time. But he knows that Nemo would never let him escape, so he has to avoid meeting him. Before the escape, however,