Marge is at the hospital with Maggie (who ate an issue of Time Magazine), making Homer, Bart, and Lisa go grocery shopping.While there, Homer and all the other shoppers insult, abuse and make unreasonable demands of the bag boys, causing all the bag boys in Springfield to go on strike. The bag boys also prevent anyone from carrying their groceries to their cars. When all the food in the house is gone, Homer becomes desperate and goes in the search of some food. Santa's Little Helper finds a 30 year old box of Animal crackers which Homer steals away and despite protests about the cookies being expired, Homer digs in without hesitation. He bites into a giraffe-shaped cracker and realizes it's made of solid gold, which means that the family has won a trip to Africa. However, when Homer goes to the company that produced the animal crackers, the executives he talks to initially refuse to give Homer and family the vacation, for a few reasons: 1.) The contest ended thirty years earlier, 2.) Their company doesn't even make animal crackers anymore (the female of the trio explains they make household poisons and Christmas lights), and 3.) "An old box of cookies" is not a legal contract. But then Homer gets hurt by the box, the executives reconsider, they don't want to be sued. Homer returns home and announces that the Simpsons are going to Africa; instantly afterwards, a tribesman in Africa tells his fellows that "evil is coming" and runs laughing crazily into the night.
When they arrive in Ngorongroro, Tanzania, the Simpsons see billboards with messages such as "Hail President Muntu", who their guide, Kitenge, informs them recently seized power. We then see the family staying in a treetop hotel, then going on safari in the Masai Mara, visiting Olduvai Gorge, and spending a day with some Maasai tribesmen. The family then join the tribesmen in a tribal dance, and Homer, while attempting to play the drums, accidentally beats the rear end of a hippopotamus, which enrages it. They use a tribal shield as a makeshift raft to escape down the river, but take a wrong turn, get swept over a waterfall, and end up far from the Maasai village. Suddenly, a chimpanzee appears, and lead them to "Joan Bushwell's Chimp Refuge", which is run by Dr. Joan Bushwell (who is voiced by Tress MacNeille). Dr. Bushwell tells the Simpsons that she is in Africa because she is researching chimpanzees, but, when Greenpeace arrive at the refuge, the family discover that she has enslaved the apes and is making them work in a diamond mine beneath the refuge. Fearing the repercussions for what she has done, Dr. Busswell attempts to bribe the Simpsons and the people from Greenpeace with handfuls of diamonds. The next scene starts with the family sitting on the plane to go back to Springfield, with all of them but Lisa carrying a small fortune in diamonds. Out of the window of the plane, they see a new billboard which reads "Hail President Kitenge", with a picture of their old guide in the presidential robes that Muntu was wearing earlier in the episode. Marge asks, "What happened to President Muntu?" Muntu then appears dressed as a flight attendant and says, "I don't want to talk about it." Muntu begins handing out peanuts, and the family all laugh as the plane takes off.