While hammering in a sign warning of the presence of ionized gas, Professor Robinson is overcome with noxious fumes released from a crack in the ground and passes out. Dr Smith meanwhile has been told to lay some dynamite charges in a drill site. Instead he tosses them in a marshy bog, leading to some kind of chemical reaction. These events together form the basis of the ‘scientific’ natural-causes explanation for the creation of the ‘ghost’ that will terrorize the Robinsons later in the episode.
Dr Smith looks for some scarlet paint to decorate his Ouija board. He is trying to contact the spirit of his great-uncle Thaddeus. Will thinks it’s very silly. Maureen ridicules the Ouija board, saying “It’s quite obsolete in the world of computers”. Smith holds the séance. Creepy organ music plays in the background. The Ouija board begins floating in the air.
But a mere handful of the many, many Hollywood films over the years that have featured the use of Ouija boards –
The next night strange happenings commence. Outside the spaceship objects are tossed about as if by an invisible hand. Giant three-toed footprints are seen on the ground. John and Don are both attacked by an invisible creature that consumes energy. Smith insists the unseen force is his great-uncle Thaddeus who has been offended by the Robinson’s denying his existence.
Dressed comically like a monk, Smith attempts an exorcism equipped with mystic charms including a ceremonial dagger and a clove of garlic. The Robinsons have their own plan to rid themselves of the creature using a cage fitted out with electronic components. In the end neither method is required. At daybreak, in classic vampire tradition, the creature instantly vaporizes.
The apparent effect of Ouija boards (first ‘invented’ in 1890) as a fanciful communication device can be explained by science with something known as the idemotor effect. You can read more about that HERE. To see how ineffective Ouija boards are when the participants are blindfolded check HERE
Check out this classic picture from 1962 of actress Angela Cartwright (Penny Robinson) meeting The Beatles.