Claire Beauchamp Randall, a nurse in World War II, mysteriously goes back in time to Scotland in 1743. There, she meets a dashing Highland warrior and gets drawn into an epic rebellion.
After their father is murdered under mysterious circumstances, the three Locke siblings and their mother move into their ancestral home, Keyhouse, which they discover is full of magical keys that may be connected to their father's death.
Having gone missing seven years ago, the previously blind Prairie returns home, now in her twenties with her sight restored. While many believe she is a miracle, others worry that she could be dangerous.