In the countryside of England, the Duc de Richleau a.k.a Nicholas welcomes his old friend Rex Van Ryn that has flown to meet him and Simon Aron, who is the son of an old friend of them that had passed away but charged them the task of watching the youngster. Nicholas and Rex unexpectedly visit Simon that is receiving twelve mysterious friends. Sooner Nicholas, who is proficient in black magic, learns that the guests are member of a satanic cult and Simon and his friend Tanith Carlisle will be baptized by the powerful leader Mocata to serve the devil. The two friends abduct Simon and Tanith expecting to save their souls but Mocata summons the Angel of Death and the Goat of Mendes to help him in a battle between the good and the forces of evil.

The time of the French revolution, and Citizen Robespierre is beheading the French aristocracy. When word gets to England, two noblemen, Sir Rodney Ffing and Lord Darcy take it upon themselves to aid there French counterparts. Sir Rodney is a master of disguise, and becomes "the black fingernail", scourge of Camembert and Bidet, leaders of the French secret police...