On Mongo, Flash and Dale spot flying "disc-ships" traveling from the planet Misto to attack Earth. They follow the ships to Earth, where Flash destroys the fleet, except for the ship of commander Wongee, who disables Flash's ship. Flash attaches his ship to Wongee's and after a mutiny against Wongee, Flash and Dale are taken to Misto. They escape from the ship and find themselves in the midst of a rural area. A friendly peasant, Agricula, hides them and then they make their way to the Queen's palace where they find that Wongee is enacting his plans to overthrow the throne.