Amazing things happen when the grouchiest family meets the nicest one!

The Yowler family is always in a monstrously bad mood: Papa grumbles, Mama yells, Sara and Sonya bicker, and the baby fusses day and night. They're so used to being grumpy that when their new neighbors smile at them, the Yowlers are puzzled and are immediately suspicious. And when the new kids ask Sara and Sonya to play? Well, that's just plain odd. Then again, it does feel good to be treated kindly . . . and all of a sudden the sisters start acting nicer themselves, causing Mama and Papa to wonder if they're coming down with something. But as it turns out, even the smallest acts of kindness can be powerful. The niceness is contagious-and it's spreading!