Fact1: village chief allows Woo-ryong and son to stay at house, Fact2: American doctor at hospital in Seoul treat Young-nam, Fact3: Mi-sook lost husband and child in war, Fact4: rats do n't fall for traps and poisons, Fact5: Woo-ryong volunteers to get rid of rats in exchange for price of pig
Output: In the 1950s after the Korean War, a gentle wandering piper with a limp, Wooryong, and his sick young son, Youngnam, are enroute by foot to Seoul through the central Korean highlands when they reach a remote village. The village chief allows Wooryong and his son to stay at his house. The piper shows the Chief an Englishwritten note that he says is the name of an American doctor at a hospital in Seoul who can treat Youngnam. The Chief, who tells the piper not to tell anyone else the war is over, agrees but he cannot read English either. Wooryong is smitten by a villager called Misook who lost her husband and child in the war. Wooryong quickly sees that the village is plagued by rats that dont fear humans and dont fall for traps and poisons. The chief explains he and his people came here when they heard Chinese soldiers were approaching their old village. They hid the village lepers in a cave with the villages original shaman. But when the Chinese had not reached the village, they returned to the cave but found all the lepers were dead and being eaten by rats. The vicious vermin then invaded the village because it had no shaman to keep them out. Wooryong volunteers to get rid of the rats in exchange for the price of a pig that will help pay for his sons medical treatment. He spreads a special powder across the village and goes to a nearby hilltop. Checking the wind direction he lights a very smokey fire that smothers the village in smoke. At the same time, Misook, who has been forced by the chief to become the new village shaman begins a purification ritual with bells. Rats start pouring out of the buildings following Wooryungs powder to a cave. Misook starts to fall in love with Wooryung due to his kind nature. The son even starts to call her mummy. However, the chief threatens her if she plans to leave the village. He also plots with his son, Namsoo, to not reward the Piper for getting rid of the rats. First they create doubt in the mind of the male villagers making them believe that Wooryong is a communist spy who brought the rats with him. At a village meeting, the chief says he is going to pay the piper but a dead cat is found. Proof the chief says that the rats are back. He holds up Wooryungs English note and says its spying material; it simply reads Kiss my ass, monkey  no American doctors name just a cruel joke. Wooryung reaches for the money but Namsoo chops off two of his fingers with a knife. The villagers turn on Wooryung and Youngnam, even Misook condemns them. But as the villagers get ready to throw them out, Misook returns in a shamanic trance but stabbed in the stomach. She tells the villagers that on a day without sun they will all die and their children might live or die, repeating the prophecy made by the villages original shaman just before she was burnt alive by the villagers. Misook then dies from her wounds. Before they leave, the Chief puts two poisoned riceballs in Wooryungs knapsack. The injured piper falls asleep while his son sneaks back to the village to retrieve his fathers pipe from the Chiefs house. On the way back, Youngnam eats one of the poisoned riceballs and dies. Wooryong sets out on a revenge. After burning his sons body on a funeral pyre that makes so much smoke it blocks out the sun, he covers himself in the special powder he used earlier to attract the rats and reopens the cave. He uses his two severed fingers as bait and starts playing his pipe to lead the rats back to the village where they devour all the adults including the chief and his son. Next morning only the villagers children are alive, Wooryung plays his pipe and leads them to the cave where he trapped the rats. After sealing them all in, he turns and looks hard into the camera.