Sixth-grader Zoe Richards is faced with the task of collecting evidence that a local factory is dumping toxic waste in her town's river. She must gather the evidence but at the same time keep her super powers a secret.

Lisa convinces the locals to clean up the polluted Lake Springfield after a crowd of fans sink the Green Day concert stage. Meanwhile, Homer saves a pig from being killed in Krusty Burger and adopts it, calling the animal Spider Pig. After two days, Spider Pig fills up a silo with its excrement and not knowing what else to do, Homer dumps the silo in the lake, polluting it. The angry population forces the Simpsons to move to Alaska. Meanwhile, the...

In Seoul, an American army doctor forces his assistant to dump bottle after bottle of formaldehyde into the drain. The drain runs into the Han River, the major river running through the middle of Seoul. His only reason is that the bottles are covered with a layer of dust. Six years later, a food cart operator, Gang-du falls asleep every time his dad, Hie-bong, is away from the stand for more than a few minutes. Soon, his daughter, Hyun-Seo returns...