"Mary thinks solving a mystery is so easy, and she isn't impressed by Harry's detective skills. So when he challenges her to figure out what secret treasure he's hiding in his giant suitcase, she jumps at the chance. If Mary can crack the case, Harry will hand over his prized, brand-new Magneto Cat. But if she can't, she'll have to make a poster saying, "Harry Spooger is the Fifth-Best Detective in the World." The stakes are high, so all the kids in Room 3B pitch in, following a trail of pink clues from the playground to the library and even to Grampa Spooger's nursing home. But will solving Harry's mystery turn out to be horribly harder than anyone had thought?"--(p.4) of cover.