Tweek is watching TV and learns that children are not safe. With fear of child abductions, his parent's talk to him about the fact that they have installed new locks on his windows and doors and that he should never allow anyone, other than his parents into his room. That night they test him and he fails. They remind him of the danger of talking with strangers. When he goes to the movies with the other boys he freaks out when he doesn't recognize the ticket taker, so he runs away. He keeps running into strangers asking him for help, so he keeps freaking out and running away. Later that night "The Ghost of Human Kindness" comes to reform Tweek. The ghost shows him examples of human kindness that always gets overlooked by the news. "The Ghost of Human Kindness" turns out to be a child abductor named Frederick Johnson who is caught. The outraged parents demand that the mayor take action. The parents suggest a way to keep unwanted strangers out of their town, build a wall around it. The mayor and parents appeal to the owner of City Wok to build a wall for them around the town. The City Wok owner builds them a "Great Wall" like the one his own ancestors built centuries ago. With the wall completed the City Wok owner finds that some Mongolians have come to try knocking it down.
Stan's parents purchase a Child Tracker, which Stan must wear on his head like a helmet. He worries about being seen in it, but he has nothing to fear, since all of the children are now wearing them. The Mongolians make another assault on the "Great Wall." The South Park Cows baseball team finds that they must play against no one, since the "Great Wall" keeps everyone out. A new study comes out that indicates that most child abductions occur by someone the child knows in their town. The parents immediately take their children home. The City Wok owner plans to defeat the Mongolians with a heat-seeking missile surprise; they divert it by throwing a flaming baseball back at the owner. The parents wait at the bus stop with their children and then attend class with them.
The City Wok owner plans to use a sweet and sour pork concoction on the Mongolian's heads. The Mongolians deliver a Trojan Mongolian Horse to the gate. The owner, knowing what is going on plays their game, only to be surprised when he is covered by the contents of the horse, a sweet and sour pork concoction. The news reports more facts about child abductions; it turns out most abductions are done by the child's parents. To reduce temptation, the parents send their children out on their own. The City Wok owner is licked free of the sweet and sour pork by a dog. The parents wonder where their children have gone. The children have found a safe haven for themselves; they are living with the Mongolians.
The City Wok owner makes his last stand to protect the "Great Wall." The boys help the Mongolians to blow a hole in the wall. Their parents see them on the other side of the wall and begin to realize that they've overreacted to all the sensationalistic news reports. The parents fear that their children don't recognize them. Stan comments on how stupid their parents are and Kyle tells the parents it has only been four days. The parents work to renew their bonds with their children. Tweek's father comments that the "The Ghost of Human Kindness" was right all along. Randy Marsh thinks it was the Mongolians who proved that walls built around things need to be knocked down to bring people together. The mayor tells the City Wok owner to tear down the wall. As Stan goes home with his parents he comments to Stan that their parents have done some really stupid things in the past, but this one…