1- Ruff upsets Mr. Wilson's painting equipment then runs over his canvas with purple paint paws. To Mr. Wilson's disgust, the resulting work is judged a masterpiece. 2- Instead of Ruff's new dog house, the postman leaves a disappearing box in which Dennis, Joey and Ruff are transported to dog city where humans are not allowed. A talking Ruff remains faithful and rescues the boys from prison and they are transported home again. 3- While Dennis is watching a neighbor's baby, PeeBee comes over with a new formula that makes things grow enormously. The baby drinks it, grows to twenty feet, and plays with real cars, water towers, and lampposts like they are toys. PeeBee comes up with an antidote just as Mrs. Mitchell returns.