Betty Jo wants to enter Dog in a contest to make a commercial for Tailwagger Dog Food. The winner also receives a $500 cash award. Kate tries to discourage Betty Jo because Dog doesn't have a chance against purebreds. The girls are thrilled when they receive a letter telling them that Dog is one of the five finalists. The letter also says that Mr. Talbot with the dog food company will be coming by to see Dog. What they don't know is that Henry Brewster, the local photo-finisher, who sent in both his and the Bradleys' entries, got the pictures interchanged. This means that Mr. Talbot was really naming Henry's collie one of the five finalists. But after meeting Dog, Mr. Talbot has an idea for a whole series of other commercials. He would like to use Dog and the entire family. Uncle Joe's meddling may ruin everything and Dog may have a say in how things go.