Occult investigator Quincey Morris and his "consultant", white witch Libby Chastain, are hired to free a family from a deadly curse that appears to date back to the Salem witch trials. Fraught with danger, the trail finds them stalking the mysterious occult underworlds of Boston, San Francisco, New Orleans and New York, searching out the root of the curse. After surviving a series of terrifying attempts on their lives, the two find themselves drawn inexorably towards Salem itself - the very heart of darkness.