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 such an expert as Aronnax, maintaining the secrecy of his existence requires never letting them leave. Aronnax and Conseil are enthralled by the undersea adventures, but Ned Land can only think of escape. They visit many places under the ocean, some real-world and others fictional. The travelers witness the real corals of the Red Sea, the wrecks of the battle of Vigo Bay, the Antarctic ice shelves, the Transatlantic telegraph cable and the legendary submerged land of Atlantis. The travelers also use diving suits to hunt sharks and other marine life with air-guns and have an underwater funeral for a