The Stickyfinger family fishes from the lake a strange fish, which when eaten, causes John Stickyfinger's face to have spots. Soon after, everyone that has fished or has taken a bath in the lake starts to suffer a similar transformation. The Handy family starts to investigate. Matthew discovers that the lake has been polluted by toxic waste which was pumped from the Putrefaction company, whose owner is Darkhand. Mayor Cleanhands, with the help of his secretary, Righthand, decides to enter the lake to calm down the public outcry. As a consequence, the mayor will suffer the same transformation process. Matthew is able to find an antidote that will cure all those who are affected. Darkhand will be punished by paying from his pocket the complete purification of the water in the lake.