The episode begins with
Cartman directing the other boys through a forest in search of a
leprechaun. A skeptical
Kyle makes a bet that if Cartman can prove leprechauns exist, Kyle will
suck Cartman's balls, but if not, Cartman will owe Kyle $10. To Kyle's shock, they find a leprechaun and chase after it. They eventually catch it in a
trap. The leprechaun says he was sent to warn of a
terrorist attack, and that being chased by the boys has made him late, before vanishing. A triumphant Cartman declares that Kyle must suck his balls, but Kyle initially refuses, asking why a leprechaun would be warning of a terrorist attack and insisting that there has to be a logical explanation. The next day, as Kyle is conversing with
Stan,
Kenny,
Jimmy and
Butters, a strange man suddenly appears, asking them if they have seen the leprechaun. When Kyle argues that leprechauns are just imaginary, the man tells him that just because something is imaginary does not mean it is not real. He then invites the boys for a ride in his magical "Imagination Flying Machine" while he serenades them with "The Imagination Song". The group arrives in a place called Imaginationland, where all the beings created by human
imagination reside. The imaginary creatures are all fascinated by the presence of "creators", and ask them about the leprechaun. At that moment a band of
Islamist terrorists suddenly appear and set off a series of bombs, which kill hundreds of the imaginary creatures and destroy most of the city, with Stan watching. The boys flee on the back of
Draco who flies them to safety. Butters, however, gets left behind, and he and the surviving imaginary characters are taken hostage by the terrorists. The next morning, Kyle wakes up in his bed, and is at first sure the whole thing might have been a dream — until he calls Stan who tells him the same story. They also discover that Butters is missing, much to his parents' shock. Meanwhile, Cartman, angry that Kyle has refused to fulfill his part of their agreement, takes Kyle to court, where the judge sees the contract Kyle signed and orders Kyle to suck Cartman's balls within twenty-four hours or he will be arrested. The
United States Department of Defense has received a video from the terrorists, which shows they are holding the survivors of the attack hostage, including Butters. Butters reads a note from the terrorists at gunpoint, and cries out to Stan and Kyle as the video ends. Unsure of how to counter the terrorists, the government officials turn to Hollywood, hoping that they can use their creativity to get ideas. After being disappointed by several directors, including
M. Night Shyamalan, who could only come up with twist endings, and
Michael Bay, who could only come up with special effects sequences, they seek the advice of
Mel Gibson, who suggests that they examine the video the terrorists sent and determine if there is anyone in it that somehow does not fit. The officials at the Pentagon immediately perform a background check on the video and realize that Butters is not an imaginary character. The general orders his men to locate both Stan and Kyle. In Imaginationland, the terrorists take one of the creatures, "Rockety Rocket", and launch him at "the Barrier", the wall that separates the good and evil halves of Imaginationland. Despite Butters' attempts to stop them, the terrorists destroy the wall and unleash the evil imaginary creatures. Cartman, meanwhile, dons a
Sultan's robe and throws a huge party, during which the other kids will watch Kyle suck his balls. Kyle has resigned himself to the task, and is about to walk into Cartman's house with Stan when members of the military arrive and take them away for questioning about Imaginationland. Cartman screams in anger about his plan being foiled, then quickly leaves home and hitchhikes with a trucker to
Washington, D.C., to force Kyle to fulfill his end of the bet. He ends the episode stating, "Make no mistake, Kyle. Before this is over, you
will suck my balls." ==Production==