In the spring of 1912, American writer Arthur Pearce is reeling from the wounds inflicted by a disastrous marriage and the public humiliation that ensued. But his plans to travel abroad, write a new novel, and forget his ex-wife are interrupted by a lovely young woman he encounters on a London-bound train. Her name is Sarah Coyle, and the tale she tells him chills his blood.

According to Sarah, her younger sister Violet has been entranced by a local count, a man whose attractiveness and charisma are rivaled only by his shady reputation. Whispers of bizarre religious rites and experimental medicine surround Count Richard Dunning, though no wrongdoing has ever been proven. Sarah’s family views the Count as a philanthropist and a perfect match for young Violet, but Sarah believes her sister is soon to become a subject in Count Dunning’s hideous ceremonies.

Smitten by Sarah and moved to gallantry by her plight, Arthur agrees to travel to Altarbrook, Sarah’s rural ancestral home, in order to prevent Violet from falling into ruin. He soon learns, however, that his meeting with Sarah on the train was no accident. And his arrival at Altarbrook represents a crucial but ghastly step in the Count’s monstrous plot.