A number of elements from the novel are believed to reflect MacLennan's life. Catherine Stewart is believed to have been inspired by MacLennan's first wife, Dorothy Duncan, who was dying of the same ailment Catherine suffers from while MacLennan was writing the novel. Another major character, Jerome Martell, is generally thought to have been inspired by Norman Bethune, a claim the author denied. MacLennan's biographer, Elspeth Cameron, points to F. R. Scott and Samuel MacLennan, the author's father, as models for Martell. However, Mr. MacLennan, in a 1965 newspaper article referring to his neurologist, Dr. Reuben Rabinovitch of Montreal wrote: “When my novel, ‘The Watch That Ends The Night,’ appeared, it was widely believed that its doctor-protagonist, Dr. Jerome Martell, was modeled on the famous Dr. Norman Bethune. He wasn’t, for I never knew Bethune. But Martell’s way of dealing with his patients was Dr. Rab’s way. This is not to suggest that Martell was modeled off him; he wasn’t. But if I had not known Dr. Rab, I could never have understood Dr. Martell." Dr. Martell's life history was also notably quite similar to that of Dr. Rabinovitch.