In The Riddle of the Massive Footprints, Olivia's world is turned upside down when she discovers enormous sneaker prints scattered throughout her house. At first, she imagines the footprints are from a giant monster, but soon, she uncovers a surprising twist. The culprit is none other than her younger brother, who's been wearing their dad's sneakers around the house, pretending to be a superhero. The shoes, however, create a slippery mess, and Olivia and her brother must race to clean up before their parents return home. Through Olivia and her brother's adventure, young readers will learn that it's okay to make mistakes, as long as you take responsibility, learn from them, and have fun along the way.