Dennis and his father go to a Boy Scout jamboree and observe (and participate in) numerous fun activities. Back at home, Dennis decides to apply some of what he learned around the house. Twisting the clothesline into a rope bridge wasn't a good idea.; Dennis' mother asks Mr. Mitchell to wear one of her dresses while she alters it. Wouldn't you know it, though, but she runs out of blue thread and has to go to the store to buy some. One thing leads to another and Mr. Mitchell finds himself locked out of his house, still wearing the dress. It only gets worse when the neighbor assumes he must be Mr. Mitchell's sister and invites him to dinner with the Ladies' Club.; Dennis has a substitute teacher in class and he drives her crazy.; Dennis dreams of causing mischief all over the world.; On a hot summer day, Dennis and Joey are surprised to see another kid wearing winter clothes. Why? He's going to visit his father at work. At the ICE CREAM FACTORY! When they're offered a tour of the place, Dennis and Joey gracefully (and gratefully) accept.