Conrad and Sally Walden live in the city of Anville with their single mother Joan. Joan works for neat-freak Hank Humberfloob as a real estate agent and is hosting an office party at her house. One day, she is called back to the office leaving the children with Mrs. Kwan, the babysitter (after the previous one quit) and forbidding them to enter the living room, which is being kept pristine for the upcoming party. Joan is also dating their next-door neighbor Larry Quinn, much to Conrad's disgruntlement because Larry is constantly on the lookout for any mischief Conrad may be up to as he wants nothing more than to send him away to military school for being a "hot-headed troublemaker".