When the Ottoman Turks launch a campaign to conquer the Imperial Austrian city of Vienna, all of Christian Europe is endangered. Volunteers flock to the threatened city, including Casca, intent on settling a score with the Turks that has been festering in his heart for two centuries.

He meets a fellow-volunteer, Peter, on the road and together two join the defending forces as the overwhelming numbers of Turks encircle the city. To nearly everyone else, it’s a simple battle for supremacy for either Christianity or Islam, but to Casca this runs deeper than mere religion.

And there are others in the city, too, who see another fight, one to capture Casca and hold him captive, for the Brotherhood of the Lamb are there, hoping to imprison the one they see as the ultimate evil. But unknown to them, Casca has an ally, a determined woman who will stop at nothing to thwart the Brotherhood’s plans.