Stan, Cartman, Kyle and Kenny are annoyed to see that a group of homeless people are taking over their basketball court. Kyle feels sorry for them and wants to do something about it. Cartman misunderstands him sets up a show where he jumps on his skateboard over a homeless person. The increasing amount of homeless people is noticed by the City Council who have a meeting of what they should do about it. After several suggestions which dehumanize the homeless, Mrs. Testaburger is the only one who is appalled at their offensive ideas. She says that the homeless are people just like them, which the council interprets as meaning the homeless have found a way to copy their DNA. Homeless Adviser of the South Park says that they must be careful to not give out any money to them, which would only bring more homeless. Kyle, still feeling sympathetic for the homeless, goes out late at night and gives twenty dollars to a beggar outside his house. The gesture goes unappreciated when the man immediately asks Kyle for more money without a thank you.
The next morning a large group of homeless have mustered outside of Kyle's home. Kyle confesses to his friends that he gave one twenty dollar bill but doesn't believe that’s the only reason why they are all there. Cartman thinks Kyle did this as a way to gather more homeless people for him to jump on skateboard. Randy Marsh, on his way home for work is swarmed by homeless people asking for change. He feels guilty and gives some change but more keep on coming, including the one he just gave to. Randy meets up with Gerald Broflovski, Jimbo Kern, and Stephen and Linda Stotch at the Community Center where they barricades themselves on the roof.
The homeless overrun the town making getting around almost impossible. Stan and Kyle see their fathers on the roof of the Community Center in a news report before the station is cut off by the homeless. The four boys go out to help their parents, where they are picked up by one of the Mayor's Aides named Ted. He tells them about the Homeless Adviser from the Council meeting and how he can help them before his car is hit by a truck and he is killed. The boys escape from the car and go down into the sewers where they head to the scientist’s house. From the Community Center Gerald decides to try to get to a bus station and bringing help. Outside, Gerald gives away his change to the homeless to get them off his back. He realizes he doesn't have any change for the bus and begins asking for his change back, making the rest of the adults think he's one of them.
The boys reach the scientist's house, where Cartman comes up with the plan to jump over all the homeless people to save those on the Community Center. Kyle, sick of Cartman talking about jumping the homeless, yells that Cartman barely cleared one homeless person. Stan misinterprets Kyle and tells him to stop arguing about jumping homeless people, which frustrates Kyle further. The scientist interrupts them and explains that the homeless live off of change like food and no matter how much you give them they'll always want more. He also says the nearby city of Evergreen faced the same problem, and managed to stop it. The homeless break into the house though and the boys escape while the scientist kills himself (after shooting himself repeatedly to no effect despite several of the shots going in his chest and brain).
At the Community Center a whole new group of people reach the roof while fleeing from the homeless. As time drags on for them things become tenser as they run low on food. Glen, a member of the City Council, calls his wife to find out what is happening when he is able to get a signal on his cell phone. His wife tells him because of the homeless, property rates in South Park have gone down. Due to this his house is being foreclosed, meaning he's homeless and this make Randy distrust him. Glen starts to panic and asks for change so he can put his things in storage, which leads Randy to blow his head off with a shotgun.
The boys make it to Evergreen which is totally destroyed. They meet three men dressed in camouflage who want the boys to leave, since being children they couldn't own homes. Fortunately the boys convince them to tell them how they solved their homeless problem. They explained they had the same homeless problem as South Park until the homeless got enough change to rent apartments and soon buy houses. This caused fights that destroyed the town because you "wouldn't know if the person living in the house right next door to you was homeless or not," not realizing of course that owning houses would have no longer left people homeless.
One of the men tells them that he had to kill his own wife who he had been living with for 20 years because she was 'homeless', because she was not the home owner in the marriage. Kyle then finds a pamphlet on the ground that advertises South Park as a great place for the homeless. The people of Evergreen didn't solve their problem, they just sent it to South Park.
In a following confrontation, the wife the man had killed is actually still alive (albeit horribly burned) and attempts to kill him, resulting in everyone dying, except for the boys. They then customize a bus to drive into South Park and lure the homeless out by singing, sending them to California, like how Evergreen had sent them to South Park (With Gerald following as well still asking for change).
In California, Cartman jumps three homeless people as Stan tells Kyle he can't see how it helps, to Kyle's annoyance.