From the back cover:
Pictland and the North in the Age of Arthur.
The wall is Hadrian's Wall, a miles-long fortification built centuries ago to hold back hordes of wild savages living north of civilized Britain. Beyond it lies Caledonia, a bleak and harsh land where feudalism and civilization have never reached. Tribal Picts, the "Painted Men," rule here. Fiercely independent, they unify only to meet threats from outsiders, whom they loath and fear. Outsiders like your knight...
Beyond the Wall features notes on generating Pict characters, a survey of Pictish customs and religions, and a map and guide to the land of Caledonia. Religion among the picts is extensively covered, including articles concerning the Celtic Christian Church and an explanation of Heathenism. Complete rules add the Shamanic tradition to the Pendragon magic system. A Pictish campaign and several ready-to-play adventures are also provided.