The winter of 1847 has brought a consumption (tuberculosis) epidemic which is devastating the village of Plumford, Massachusetts. In an atmosphere of increasing hysteria and superstition, country doctor Adam Walker and philosopher Henry David Thoreau seem the only voices of reason. The winter also brings two visitors to Plumford. Solomon Wiley hails from Rhode Island and offers his services as a vampyre hunter, insisting that the scourge is supernatural in origin. At the same time, Adam's cousin Julia has returned home from France, mysteriously without her new husband. When a former student of Thoreau is found mutilated and drained of blood in the woods, Wiley insists that a legendary Indian vampyre has arisen. Dismissing the blustering fearmonger, Thoreau and Adam follow clues to the backstage world of a Boston theater, the smoky decadence of an opium den, and an Indian burial ground. Both men will need to keep their wits about them - or risk ending up in coffins of their own...