While out looking for precious metals Will and Dr Smith see an object shining in the distance. They walk towards it and naturally it turns out to be an alien spaceship. Will goes into the spaceship. The door closes behind him. The spaceship blasts off into the sky.
Will returns after his spaceflight very different. He talks like Einstein, as if his IQ has somehow magically quadrupled. He begins tutoring his father and Don about the physics of the Jupiter 2’s atomic propulsion drive.
Though Will is now clearly way ahead in intelligence of all the adults and his older siblings he finds it difficult getting along with everyone. He informs Judy her gardening methods are primitive. He easily beats Penny in a game of chess. When Dr Smith sits down opposite Will to take Penny’s place at the chess board Will advises him “Don’t trouble yourself Dr Smith. We’re not evenly matched”.
Smith is curious to know if he was to take a flight in the spacecraft would the same change that has affected Will also happen to him. After getting instructions from Will on how to fly the ship Smith also takes a flight in the mystery craft. When he returns he has aged fifty years.
In comical scenes, the geriatric and perpetually complaining Smith, complete with flowing grey beard and wheelchair, is reduced to being spoon-fed soup from an oversized bowl by his longstanding arch-nemesis Don. Meanwhile John and Don engineer the spaceship to reverse polarity during flight thereby hopefully reversing the molecular change effect.
Smith convinces Will to take a test flight to see if the changes made to the spaceship will work. Will blasts off again in the spaceship and returns with his normal IQ level restored. An alien also emerges from the craft and promptly launches the spacecraft once more, this time with Smith aboard.
Believing Dr Smith has been kidnapped and will never return, the Robinson’s hold a memorial service in his honor. Finally the spacecraft does come back with Dr Smith emerging, returned to his normal age. He marks the occasion by observing –
“To paraphrase a nineteenth century master of the written word ‘The report of my disappearance seems to have been greatly exaggerated’.”
Imagine Smith saying this and it’s even funnier…