In a way to spite Lisa, Bart makes a prank call to Tobias Drundridge, a naive Australian boy, which sparks international controversy.
The episode begins with a bathroom products race between Bart and Lisa at the bathroom sink. Lisa wins and Bart suggests she won because her shampoo was in the "inner lane" to his toothpaste. Lisa explains the Coriolis Effect to Bart not entirely correctly, but he doesn't believe her. He then tries draining the sink and flushing the toilet, the water not only goes counterclockwise but it also changes the temperature in the shower for Homer. Lisa tries to explain the effect to Bart more specifically by using Bart's globe, (which he never opened). Bart then tries to prove that the effect is not real, he makes several international calls. After calling many other Southern Hemisphere countries, like Argentina, Chile and a fictional African dictatorship, without getting an answer he soon makes a collect call to an Australian boy, and asks him about which way the water drains, the boy confirms that the water is draining clockwise (Bart is angry but covers up.). He then asks the boy to see if the neighbors water is draining clockwise as well. The line is kept open for several hours, when Bart doesn't hang up, the Australian boy's father is billed $900.00, even the Simpsons family gets a big phone bill. The man wants Bart to pay, but gets mocked by him. Unfortunately for Bart, the man's neighbor is a Member of Parliament, who reports Bart's offence to the Prime Minister. Bart receives dozens of collection letters in the mail, but turns against them and simply places the letters in his wastebasket, along with Lisa's Sax. When Lisa sees how full Bart's waste basket is, he thinks this as not a big deal until Lisa reads all the letters.
Eventually, Australia indicts Bart for fraud, and soon enough The State Department comes by to explain that because the country's relationship with Australia is not very good at the moment, Bart's offense has only worsen the whole thing. To help pay back to their friends in Australia, The State Department wants to imprison him for five years, Homer thinks that's fair but Marge is against that idea. They soon settle upon having Bart personally make an apology in Australia. The family is sent and flown to Australia, where they start exploring the culture. Bart brings a bullfrog with him and puts it in a fountain because he doesn't want to get into more trouble and promises to come back to get the frog. The frog runs off and meets a kangaroo and goes into the kangaroo's pouch. On the way in, Homer sees a marine at the American Embassy and mistakes the marine to be a Queen's Guard and makes fun of him and so then gets knocked out. Later, when Homer leaves the embassy, the marine reveals that the embassy is American land and Homer jumps in between the countries and gets knocked out by the marine again. Marge, Lisa, and Maggie go to a museum, where they see Australia's first Prime Minister who looks like Snake.
Bart goes to the courts and makes his apology, but they want to give the additional punishment of a boot to his bum (a parody of the Michael P. Fay caning incident in Singapore). Homer cannot believe that Australia would do something like this but he is warned not to speak out against this as it is a tradition of Australia. Homer and Bart escape the booting and gets chased back to the embassy. The American Embassy tries to keep out the Simpsons, but fails due to a malfunction from the gate and after the Simpsons come in, the soldiers close the gate manually keeping out the enraged Australians. Bart agrees to a booting from the Australian Prime Minister, but with a normal shoe and only once; however, as he is about to receive his punishment, he dodges the kick from the Prime Minister. Then Bart moons the Australians with "Don't tread on me" written on his bum and hums "The Star Spangled Banner."
The citizens break down the gate and pursue the Simpsons, causing the family to leave the country in a helicopter in a scene similar to the Fall of Saigon with the Australians throwing Fosters at the Simpsons. A subplot through the episode where Bart brought his pet bullfrog into the country past customs, where it reproduces and spreads rapidly throughout the country and ruins Australia's ecology (a reference to the actual introduction of non-native Cane Toads into Australia).
As the family is being flown home, they happily remark upon the destruction that can be caused by introducing a foreign species into a new environment - as the camera pans out to reveal a koala hanging from one of the helicopter's struts. The camera zooms in on the koala, finishing with a closeup of one of its eyes, implying that the U.S.A. will face a similar threat from Australia.
Behind the Laughter
This episode marks the first time the family has visited another country.
In Australia, the episode was met with criticism due to its hugely inaccurate and stereotypical portrayal of the country, although it has been accepted as typical American satire and is still aired as a re-run as often as all other episodes. Some Australian fans of the series rather consider it an honor that Australia was featured so much in an episode at all. Subsequent Simpsons episodes exploited existing stereotypes of other countries, but this episode actually fabricated things about Australia wholesale, as the Simpsons producers admit in the DVD commentary for this episode.