Commander Shore and Phones are taken prisoner by Idotee who uses an old Spanish galleon to attack ships. Shore demands that Troy launch Sting Missiles against the galleon but the Captain disobeys orders and boards the vessel. There he opens his air cyclinders in the control room but unknown to Idotee the cylinders are filled with laughing gas! The alien is laughing so hard he fails to realise that he's captured

While the Stingray crew go to the rescue of two crazy treasure hunters, Troy falls down a crevasse, runs out of air and goes into unconsciousness. When he comes to, he discovers he doesn't need breathing equipment to breathe and he is now the richest man in the world.

Lt. Fisher takes command of Stingray in his training to become an Aquanaut. The exercise involves target practice on a Terror Fish target but X20 has attached a sticker bomb to one of the targets and one to Stingray's hull. Troy is air-dropped into the sea in an attempt to remove the bomb from Stingray's hull before it explodes.

An underwater alien takes an ex-WASP admiral and his wife captive.

Commander Shore is framed when a piece of equipment disappears from Marineville control. Troy places the commander under arrest but who would want to frame the commander and why doesn't Shore protest his innocence?