The Winter Soldier is a 2018 historical novel written by Daniel Mason. Set in 1914 Vienna, it tells the story of Lucius, a 22-year-old medical student, and a field hospital nurse following the outbreak of World War I. The novel focuses on themes including war, historical medical practices, family, and the role of chance in the formation of relationships, history and penance. It also describes the origins and early treatment of what Mason describes as "a new disease, born of the war", post traumatic stress disorder.