Set against the tumultuous backdrop of World War I and the social upheavals of early 20th-century England, the story follows Christopher Tietjens, a principled and stoic British aristocrat, who navigates the complexities of loyalty, honor, and love in a changing world. Christopher finds himself caught between his marriage to Sylvia, a manipulative and unfaithful socialite, and his profound feelings for Valentine Wannop, a young suffragette who represents a stark contrast to his wife in both ideology and temperament. His personal dilemmas are compounded by the societal expectations of his class and the tragic global conflict that challenges the very foundations of his worldview.

As Christopher is thrust into the horrors of trench warfare, his internal and external conflicts mirror the fragmentation of the society left behind. The war not only tests his physical and emotional limits but also forces him to question the rigid codes of morality and duty that have hitherto defined his life. Meanwhile, Sylvia and Valentine, along with a host of other characters, face their own battles on the home front, grappling with issues of fidelity, independence, and the quest for personal fulfillment amidst the ruins of a crumbling social order. The narrative weaves these individual stories into a rich tapestry that explores the themes of love, betrayal, and the quest for integrity in a world beset by moral ambiguity.