I reread the book during this project and the part that stuck out the most to me was when he (Wiesel) was on the train headed to Auschwitz and there was a woman on the train who would randomly and aggressively shout about being able to see the flames.
Out of fear, she was then aggressively beaten by the people on the train in an attempt to get her to shut up.
She was referring to the flames of the crematorium at Auschwitz, but each time she shouted this there was nothing in sight.
