What do we learn about McLeod's disfigurement over the course of the novel, The Man Without a Face?

Over the course of the novel, we learn that McLeod's disfigurement was caused by a car accident. McLeod was drunk and driving with a young boy in the car when the accident occurred. The boy died, and McLeod was badly burned. Soon after, McLeod lost his teaching position at St. Matthews and ultimately served two years in prison.