This rollicking ride began as a bedtime story for the author's children, and years later is finally down on paper. The story starts calmly enough in the classroom, but quickly changes pace into an over-the-top adventure, reminiscent of Indiana Jones, complete with secret doors, laundry chutes, a car chase, hidden caverns and a thousand-year-old mystery. The danger is real for the children -- they are threatened with a stiletto knife, cut on the leg with a sword, and suffer various bumps and bruises from climbing and falling. There is some blood and violence and a few adult characters die at the hands of other adults, though not in a graphic way. There is mild language: arse, h-ll, d-mn. All told, with the complexity of the plot, the violence and language, this book is probably best-suited for older tweens or young teens.