The Gruffalo, written by Julia Donaldson and illustrated by Axel Scheffler, is a captivating story about a clever mouse who outwits various predators in the deep, dark woods. While not strictly a mystery book, the suspense and anticipation of whether the mouse will be able to escape the Gruffalo's clutches adds an element of mystery to the story. This book is a modern classic loved by children and adults alike.