Teacher Nathan Brookes leaves four pupils alone during a field trip in a national park. Within minutes, they have disappeared. A girl called Liv returns, but she has no memory of where she's been. When a body is found years later, it is first believed to be one of the children, but is identified as a Bronze Age man. Yet Nathan starts to have horrific visions of the missing students. Then Liv reappears, desperate that the man be reburied. For he is the only thing keeping a terrible evil at bay...