Captured and tortured by the English during Longshanks' war against the Scots, Ronan MacGrigor finds the strength to escape only to suffer the fear and rejection of his own clan. Forced to stalk the shadows at night, Ronan becomes a prisoner of illness, fear, and memories. Fearing for his life, his brother summons a healer whose reputation borders on that of a miracle worker, but she comes from the land of the Sassenach, the very people who tried to destroy Ronan.

A foundling, Lia knows little about wars or politics; she knows only how to treat the wounds they create, and her dedication to healing knows no borders. But the Demon Laird cannot abide a Sassenach within his home, and when a mysterious plague strikes the villagers, he looks to the woman of an enemy nation to be its cause. Even in the face of Ronan's hatred of her and the superstitious fear of the clan, Lia knows she must stand for the truth.

Despite their fear of him, Ronan's only goal is to protect his clan from the vicious war raging around them, but when the enemy is at his gates, the Demon Laird must answer. Lia wages her own war, that of healing the soul of a tormented laird - where all others have fled in terror, she refuses to run.

The villagers whisper of a curse - the Demon Laird made a deal with the devil - now the devil demands his due.