Gotcha! Gotcha Back! — Nancy Krulik

Katie and her friend George try to spice up the school day by playing a few practical jokes. Using a special kit full of whoopee cushions, pepper gum, and a water-spraying camera, the two kids make a splash pulling off gag after gag. But then Katie turns into George -- just as he gets blamed for all the trouble! How will Katie get out of this one?