Roger asks Doug to take care of his cat, Stinky, while he goes on a trip. Stinky not only rips up the Funnie home but also eats all the junk food in the house and gets sick. Doug rushes him to the vet, hoping he'll be OK. But when Doug gets there, he finds out Stinky isn't a "he". Someone has sabotaged the wheelbarrow race at the Bluffington picnic and now no one can be in the race. So, Doug and Patti team up to solve the mystery of who did it and why.