The story follows Christopher Tietjens, a wealthy member of Edwardian England's upper class, as the country is drawn into World War One. Tietjens is at the center of a love triangle between his wife Sylvia, a treacherous socialite who is trying to destroy him, and his suffragette mistress, Valentine. The warfare Tietjens encounters as an officer in Europe is but a backdrop to a personal battle of conflicting loyalties, hidden passions and the rigid social expectations of his day.