30-year-old fraternal twins Tabby and Sage Winslow own The Book and Candle Shop in Savannah. Sage is hot-headed and impulsive while Tabby is calm and collected, making them the perfect partnership. When one of their customers is found murdered, from a blow to the head, that partnership is put to the test. Blithe McAdam had been seen in a heated argument with shop clerk Gerard, which immediately makes him suspect number one. The twins are convinced of Gerard's innocence and start digging into Blithe's past. But no one is cooperating. The neighbor who found the body isn't talking, medical examiner Quig won't give any details about the autopsy, and nasty rumors begin surfacing about the drowning of Blithe's father years earlier - evidence that could seal Gerard's fate. Tabby and Sage dig desperately for the truth. But it's not only their friend who's in peril. With the clock ticking, the twins find themselves in the grip of an unseen and deadly energy that has seeped into their midst - and in the sights of a ruthless killer.