Class has started, but the science teacher Mr. Bluni is nowhere to be found. Instead, he's left a riddle about underground resources on the chalkboard for Mary Catherine and her friends to solve. Can the class figure out which natural resource Mr. Bluni means? This engaging play introduces readers to important facts about water, from exploring the water cycle to discovering underground aquifers. Beautiful illustrations and humorous jokes entertain readers. This amusing and educational play is the perfect tool for introducing students to water conservation.