Pip, Bets, Larry and Daisy had misunderstood Ernest "Ern" Goon, Clear-Orf’s nephew as their good friend Fatty in one of his disguises. They even called him Fatty and Bets gave him the Christmas present meant for Fatty, a notebook with his name on it. However, when Ern tells all this to Mr. Goon, the policeman suspects that the children are solving another mystery and asks their parents to ban them from solving another mystery. But as Ern asks the children repeatedly of telling him of a mystery, the children make up a fake mystery and tell it to Ern, telling him about kidnappers and robbers on Christmas Hill, hoping that Ern would tell Mr. Goon and that the policeman would try to solve the false mystery.