Survivors of a sinking ship are rescued by Captain Nemo and his submarine crew. They are taken to an underwater city where they may spend the rest of their lives.
Colonel Proudfoot of Proudfoot Industries tries to entice a couple of newly qualified dentists to advertise "Dreem", a revolutionary type of toothpaste, but he knows that if the dentists learn that they are part of an advertising campaign, they will be struck off, and the campaign will be a disaster.
The Mediterranean, 1941/42 - Axis forces are using frogmen and manned torpedoes to attack previously impregnable harbours. The Allied forces need to come up with something to answer this threat, which they find in the form of Lt. Lionel "Buster" Crabb.
