The Dragon in the Stone by Allan Scott

Blackened and half-forgotten in a Danish churchyard stands an ancient runestone - the secret gateway to a twilight world where supernatural powers battle for the fate of our world.

Erik Larssen has become a part of that conflict, searching for his lost son in a world beyond time. But it is Peter Brockman, a young American archaeologist, who will hold the world's fate in his hands. And it is his courage and his love that will be put to their ultimate test when he finally confronts the terrible Watcher - the Dragon in the Stone.