from The Introduction: The investigators travel from Essex to Northumbria in an attempt to track down Rollo One­Eye’s daughter Unn, who in turn may lead them to her master­ the mysterious “Wanderer”. On her trail, they find a pestilent village and become infected. They soon discover the secret Odin Mine where the serpent man has been excavating the Blue Stone, confront Unn, discover some of the serpent man’s plans, and hopefully an antidote for their infection.