On a volcanic island close to the Kingdom of Hetvia guidelines Depend Dakkar, a benevolent chief and scientist who has eradicated class distinction among the many island's inhabitants. Dakkar, his sister Sonia and her fiance, engineer Nicolai Roget have designed a submarine which Roget pilots on its preliminary voyage simply earlier than the island is overrun by Baron Falon, despotic ruler of Hetvia. Falon units out after Roget in a second submarine and the 2 craft, diving to the ocean's ground, uncover an odd land populated by dragons, large squid and an eerie undiscovered humanoid race.
