From the back cover: "Tyler and Freckle are amazed when they see a building rise up and disappear before their eyes. When the building reappears they take their chances and enter Quigley's Bike Shop. But it seems that Quentin Quigley does more than repair bikes. When the boys discover a secret room filled with unusual artwork and inventions, they wonder about Mr. Quigley's true identity. Before they find out, Tyler and Freckle get trapped in one of Mr. Quigley's inventions and, ready or not, they travel back through time wondering if they will be stranded in the past forever."