MacLennan modeled the character, Jerome Martel, on the life of Canadian surgeon, Norman Bethune, who served in Spain, where he founded a mobile transfusion unit, and in China, where he died working as a field surgeon under Mao ((see film annotation, Bethune: The Making of a Hero). Like Bethune, Martel has difficulties with his Montreal colleagues who respect his skills, but mistrust his commitment to social justice and his fascination with communism. Maclennan provides vivid descriptions of life in a 1920s New Brunswick logging camp, where Martel spent his childhood, and of Montreal in the 1930s and 1940s.