After their spaceship takes off with Jerry and Alice inside, Fi and Fum attempt to return them home but end up in the far future . While exploring, the kids are arrested for not having numbers and for exposing their faces in public.
When the lost saucer crashes into the underwater city of Atlantis, ruler Nepto converts the saucer into a TV station and forces Fi and Fum to perform for the cameras.
When the saucer lands on 25th century Earth, they find that all power supplies have been depleted, so three rebel scientists attempt to use the Dorse to operate a treadmill generator.
When Fi and Fum return to their home planet with stray travelers Alice and Jerry in tow, Commander Stickler decrees that the androids must be recycled.
The space travelers land on their home planet in the future and discover people have reverted to the stone ages, and they find themselves terrorized by a half-chicken, half-elephant creature.
The crew find themselves in a land where the laughing gas is pumped into the air and it's illegal not to smile. This is problematic for the androids, whom the gas has no effect on.
Fi and Fum are arrested and brought to court for a traffic violation, where they discover a narcissistic ruler has cloned an entire civilization in his own image.
