After surviving the horrors of the First World War, Siegfried Sassoon (Dunkirk’s Jack Lowden) returns home. Despite decorated service, Sassoon takes a stance against the government's continuation of the war, writing poems detailing his experience on the Western Front – poems that lead to adoration from members of the aristocracy, as well as stars of London's literary and stage world. Embarking on affairs with several men but broken by loss and conflict, Sassoon searches for salvation – trying to find it within the conformity of material success, marriage and religion.