The Swift and the Harrier / Minette Walters.

When bloody civil war breaks out between the King and Parliament, families and communities across England are riven by different allegiances. A rare few choose neutrality. One such is Jayne Swift, a Dorset physician from a Royalist family, who offers her services to both sides in the conflict. Through her dedication to treating the sick and wounded, regardless of belief, Jayne becomes a witness to the brutality of war and the devastation it wreaks. Yet her recurring companion at every event is a man she should despise because he embraces civil war as the means to an end. She knows him as William Harrier, but is ignorant about every other aspect of his life. His past is a mystery and his future uncertain.