The Mysterious Island is a 1929 American sound part-talkie science fiction film directed by Lucien Hubbard, based on Jules Verne's 1874 novel L'Île mystérieuse (The Mysterious Island). The film was photographed largely in two-color Technicolor. In addition to sequences with audible dialogue or talking sequences, the film features a synchronized musical score and sound effects along with English intertitles. The sound was recorded via the Western Electric sound-on-film process. The film was released by Metro-Goldwyn-Mayer.

Plot

On a volcanic island near the kingdom of Hetvia rules Count Dakkar, a benevolent leader and scientist who has eliminated class distinction among the island's inhabitants. Dakkar, his daughter Sonia and her fiance, chief engineer Nicolai Roget, have designed a submarine boat which Roget pilots on its initial test voyage shortly before the island is overrun by Baron Falon, once Daggar's friend, and now the new despotic ruler of Hetvia. The Baron has Dakkar and his daughter tortured so that Dakkar will reveal all his discoveries. Dakkar is able to escape with the intervention of his loyal men. But Falon sets out after Roget and Dakkar using the Count's second submarine. The two underwater craft dive very deep to the ocean floor, where they discover a strange land populated by dragons, a giant octopus, and eerie, undiscovered humanoid race.