Heartfire

Peggy is a Torch, able to see the fire burning in each person's heart. She can follow the paths of each person's future, and know each person's most intimate secrets. From the moment of Alvin Maker's birth, when the Unmaker first strove to kill him, she has protected him.
Now they are married, and Peggy is a part of Alvin's heart as well as his life.
But Alvin's destiny has taken them on separate journeys. Alvin has gone north into New England, where knacks are considered witchcraft, and their use is punished with death.