Hogan is demanding that Klink fix the leaks in their roof, but Klink will not. Instead, he shows Hogan how superstitious he is when he puts up an astrological chart. Hilda tells Hogan that Klink really does take it seriously and believes people have a sixth sense.
Klink has a visitor, Captain Gruber of the Third Engineers. He is covering up something on a half-track, so Hogan and Co are out to find out why. They send a football under the half-track during one of their games so they can sneak Carter in to take a look under pretext of retrieving it. Carter reports an antenna on the top and a control panel on the side hatch, but could not comprehend the control panel. Hogan has Le Beau bring out the camera. They take photos of the control panel under pretext of taking shots of Schultz posed beside it.
That night a storm has the roof leaking very badly. Le Beau is fed up with Klink not fixing the roof and decides to fix it himself. Baker comes up and reports that London has received the photos. They say it is a new development: a magnetic deviator that is designed to throw off the aiming mechanism on their radar. London wants Hogan to send the magnetic deviator to them so they can examine it and figure out how to neutralise it. While they discuss how to get their hands on the deviator, and also grumble about Klink seeing astrologers instead of fixing the roof, Le Beau goes out to fix it. But a bolt of lightning almost hits him and he falls off the roof. He is all right, but it gives Hogan an idea on how to get to the half-track: the lightning did hit Le Beau and awakened the psychic abilities from his Basque blood. He is now a gypsy who can now tell fortunes and knows everything. Well, that is what he is going to tell Klink and take advantage of his superstitious beliefs win his complete confidence. And once their little gypsy does that, he is going to tell Klink to move the guards from the half-track. And to ensure Le Beau does know everything, they sneak into Klink's office to acquire some information.
So, next morning at roll call, Klink and Schultz are surprised to find Le Beau is wearing a gypsy earring. Hogan and Co start spinning the yarn about Le Beau becoming psychic after the lightning strike. Le Beau starts using the information they gleaned from Klink's correspondence to further convince him of his psychic powers. Superstitious Klink is impressed. He takes Le Beau into his office and makes a big fuss over him while Le Beau gives more demonstrations of his 'powers', including a 'foretelling' that Klink is going to save a secret weapon in the camp - the deviator. Le Beau tells Klink that the Allies know about the deviator and will send commandos to capture it. They are going to arrive that night at the front gate. They will fail because Klink is going to set a trap for them, but he needs to send all his men to the front gate. He will be a hero and his manoeuvre will become known as the 'Klink Dipsy-Doodle'.
Klink is completely taken in, and that night he has all his men at the front gate. Outside, Newkirk stages the commando attack with firecrackers while the others steal the deviator from the unguarded half-track and leave nitro in its place to blow it up. Klink is over-confident because he believes so much in his gypsy. First he unleashes machine-gun fire and then orders his men to go out and attack. They find nothing (Newkirk has finished and returned to camp) and Klink assumes the commandos have fled. But when Klink returns, his gypsy 'foretells' that an English bomber is coming. This is their cover for why the half-track blows up. Following the explosion, Le Beau removes his earring and affects no recollection of having psychic powers.