The aristocratic Duke de Richleau faces new; sinister challenges in this macabre tale of the dark arts. When his good friend Simon Aron's naive curiosity is tested; the Duke; along with his ever-patient friends Rex Van Ryn; and Richard Eaton; must intricately plot a means of both physical and spiritual rescue. But with Van Ryn's affections for a beautiful woman caught in the web of Satanists; and Eaton's ongoing scepticism; they all risk being brought to the verge of madness through dabbling with the powers of evil. From London to the West Country; the slums of Paris to a Christian monastery; the action of this powerful occult thriller moves with fantastic; compelling force.