Max and his family plan a trip to Hadrian's Wall in England. Just as they are leaving, Max's gran gives him a very unusual warning & but Max doesn't listen. Along with a tour guide called Jefficus, Max embarks on a walk along the wall. But when the mist comes in, they find themselves in a very unfamiliar time and place. Will they be able to find their way back?

"PM Level 30"--Back cover.