The members of the Baby-sitters Club think they can handle a young practical joker, but when one of her tricks causes Claudia to break her leg, the girls know they must teach their new charge a lesson.
Recounts the events that occur at the end of seventh grade, when a group of friends plan to trick Carlos, an annoying "problem" student who says he is visited by aliens, while they are on a field trip in the mountains of New Hampshire.
Spud and Joe are determined to catch the mysterious prankster who keeps getting them into trouble when they spend their summer at Camp Custer with Mary Frances Hooley and Lamar J. Spurgle.
Having reluctantly agreed to run for sixth-grade president, Jerry, who has been trying to change his image as a dork, finds his opponent playing dirty tricks on him.
April Fools' Day turns into a bad day for Wagner the mouse when his best friend, Pearl the rabbit, and other children and adults at school play tricks on him.