At summer camp, puzzle-loving Cooper uses his detective skills to make friends and solve the mystery of the disappearing marshmallows.

RIF's 60th Anniversary Highlighted Book for 2018. Rosie Revere is no stranger to flops and fails, but when her beloved Aunt Rose and the Raucous Riveters, a group of women who built airplanes during World War II, need her help to invent something important, the pressure feels bigger than ever. With her friends Ada Twist and Iggy Peck by her side, Rosie keeps trying through every catastrophe. Can one determined engineer prove that the best inventors are the ones who never give up?