Arthur starts his own pet-sitting business to prove he is responsible enough to get a dog of his own, which includes watching over his neighbor, Mrs. Wood's, unfriendly dog, Perky. When Perky goes missing on the day Mrs. Wood is picking her up, Arthur fears that he is not a good pet owner until he finds that Perky has given birth to a litter of puppies. Arthur adopts one of Perky's puppies as payment. D.W. annoys Arthur by acting and dressing like him and following him around. Arthur's friends start excluding him because they do not want D.W. around. But when D.W.'s own friends refuse to play with her, she decides to change back to her old self.