On a lonely moor in the northeast of England, the body of a young woman is discovered near the site of a vanished church. In the south, a girl lies buried beneath a Saxon mound. To the southeast, the ruins of a priory hide a human skull. Each is a sacrifice, a summons. And something in the darknesss has heard the call. But another is coming: Parker the hunter, the avenger. Parker's mission takes him from Maine to the deserts of the Mexican border; from the canals of Amsterdam to the streets of London, he will track those who would cast this world into darkness.