Lum has hired Dr Roller the pest controller, to get rid of Abner's mouse friend Clyde, who has caused a good deal of damage in the store. By sending Abner off on a false grocery order yesterday, Lum managed to get Dr Roller to set up his patented trap without Abner's knowledge - and Dr Roller was so confident that he would catch the wily mouse, he told Lum that if he failed, he would not only return his fee, he would also give him $100!