Gerry and his son, Kenneth, had already planned a visit to explore Yeavering Bell - an ancient hill fort in North Northumberland, occupied some 2,000 years ago by the Votadini, an ancient British tribe. During the expedition, they suddenly stumble on something that leads to a major investigation involving archaeologists and scientists. This uncovers the truth about the leaders of the Kingdom of the Votadini and their battles to repel invading Angles and Saxons. Moreover, the identity of the so-called legendary King of the Britons, Arthur, is finally revealed.