Can it be that the fearsome master criminal Count Fosco yet lives? Marian Halcombe Camlet learns that Fosco escaped vengeance and has sold her husband Theo into captivity, winding his plots around everyone she loves once more! Her journey to rescue him and defeat Fosco, and incidentally to save Vaurantania from bloody revolution, takes her to the capitals of Europe and at last a grim castle high in the Alps.