The moon tunnel - Jim Kelly

From beneath a wartime POW camp near Ely, deep in the Cambridgeshire Fens, a man crawls through an escape tunnel. But he won't emerge until fifty years of peace have passed.When he does, unearthed by archaeologists seeking a Saxon burial tomb, local journalist Philip Dryden knows he has a mystery to solve. First the man appears to have been shot in the head - and second, he was breaking into the camp not out.The police treat the body as an historical curiosity, but Dryden digs deeper - and soon unearths a corpse of much more recent origin.