In this companion to Dive In!, it's a busy day on the building site and these industrious mice are up to something big! But what are they making? Bold, colourful illustrations and playful vehicles with moving parts make this book a deliciously interactive mystery, with hidden clues for the careful observer. Is that red paint? Or red sauce? Is that truck hauling rocks? Or mushrooms? Children will delight in guessing their way to the end, when the final spread reveals a carefully constructed pizza! A must read for truck and pizza enthusiasts alike, not to mention amateur sleuths.