Loosely adapted from the Jules Verne novel, this 1929 state-of-the-art cinema spectacle uses sound sequences, special effects and breathtaking cinematography to make the fantastic feasible. Hidden from prying human eyes, brilliant scientist Count Dakkar (Lionel Barrymore) has built a futuristic underground city and filled it with advanced devices with which he hopes to enforce world peace from his redoubt on a mysterious island. But Falon (Montagu Love), a trusted friend of the Count's, takes control of the island and it's arsenal and plots to conquer the Earth. Now it's up to the heroic efforts of the Count, Nicolai Roget (Lloyd Hughes) and their allies an underwater species that is part-man, part fish to foil the nefarious Falon.