Supernatural investigator Quincey Morris and his partner, white witch Libby Chastain, are called in to help free a desperate family from a deadly curse that appears to date back to the Salem Witch Trials. To release the family from danger they must find the root of the curse, a black witch with a terrible grudge that holds the family in her power.

The pursuit takes them to the mysterious underworlds of Boston, San Francisco, New Orleans and New York, stalking a prey that is determined to stay hidden. After surviving a series of terrifying attempts on their lives, the two find themselves drawn inexorably towards Salem itself ‚ ­ and the very heart of darkness.