The adventures of Corneil, the super-intelligent dog who hides his genius from his owners, until Bernie the dog-sitter finds out his secret. Bernie's cousins from the country are in town for a fair. John and Beth are away and Corneil has reluctantly agreed to let them stay with him - except they prove to be rather difficult house guests. Will Corneil be able to get rid of them and tidy the house before John and Beth return?