The next mission for Charlie and Itchy takes them to the sewers to help a colony of mice. Toxic smelling paint and other junk are washed down the drains, taking away their freedom of living without anything to worry about. Charlie and Itchy team up with Moxie, a mother mouse in the colony, to crack the case. They follow the drain to Carface and Killer's curio shop, trying to transform new looking toy trains to look like antiques to sell for loads of money. The problem is almost unbearable for Charlie to succeed in, until Anabelle tells him that the pollution in the water would someday end up in his dish.