Captain Nemo and The Underwater City - Plot

Plot

The film starts off with a ship caught in a storm. As the vessel sinks, and several of its passengers begin to drown, divers swim up to them to bring them to the Nautilus. From there they are taken to a magnificent underwater domed city, Templemir, controlled by Nemo. In addition to its Utopian lifestyle the survivors discover much of the city is made of gold. Two of the survivors, the brothers Barnaby and Swallow Bath, begin to plot to steal some of the gold. Another survivor, Fraser, is an ambassador of the US government en route to Britain on urgent business, and desperately desires to continue his mission. Another of the party, Lomax, feels claustrophobic in the city and desperately wants to go back to the surface. However, for the safety of the city and its people, Nemo tells the survivors that they cannot leave. The only ones that accept this easily are a boy and his mother, Philip and Hellena Beckett.

During their first days Fraser and the Becketts are shown the underwater farms of the city. The Bath brothers discover that a special machine produces Oxygen and fresh water for the city. As a by-product gold is also produced; as such, gold is basically worthless, and is only used as a non-corroding plating material. This makes the thieves determined to escape with as much gold as possible. During the night, Lomax is apprehended attempting to escape by stealing diving gear. Nemo lets him off easily. However he later retaliates by sabotaging the key life support systems to over pressurize the dome which will cause the city to be destroyed. However this results only in the room being flooded; Nemo responds to the danger by sealing off the room to save the city, leaving Lomax to drown.

Though the city is safe, destruction still ensues. In the process the Bath brothers are able to sneak into the Forbidden Area, a place kept off limits to all. Whilst there, they discover a second, much larger Nautilus II, a ship that looks faster and more powerful than the first. It becomes plain that if they follow through with their attempt to leave Templemir, they will have to steal this submarine.

It is equally plain that they will not be trusted by either Nemo or by Joab, his second in command. Instead, they approach Fraser, and include him in their plans. Fraser needs little urging, and after some persuasion, convinces Nemo to teach him how to command the Nautilus. During a training cruise, he is at the helm when Nautilus encounters an old enemy, Mobula, a vast Manta Ray-like creature accidentally created during the building of the city (Though not specifically stated, mutation following a nuclear explosion is inferred). Mobula attacks the Nautilus, and falls prey to the submarine's front ram.

Fraser approaches Nemo with a request that he should be allowed to leave Templemir. His reason is an honest one; his mission was to cut off the supply of weapons supplied by European arms manufacturers to either side in the recently declared American Civil War, and so prevent a much greater conflict. Fearful for his people, his city, and the possibility of his inventions falling into hostile hands, Nemo can only refuse. He counters by offering Fraser a place in Templemir's future, an enclosed undersea Metropolis of several such cities. In doing so he alienates a jealous Joab, who is easily persuaded to help Fraser and the Baths steal Nautilus II, on condition they leave cleanly, and return the submarine intact.

And so, during the All Seas Day celebration on the anniversary of Templemir's completion, the attempt begins, and the race for freedom is on.