Why is Madame Schäcter screaming?

Madamae Schaechter has just been separated from her husband and two older sons. She is on the train with her ten-year-old son and is beginning to lose her mind. She starts screaming hysterically about a fire and a furnace that she claims to see in the distance. At first, she terrifies the people in her wagon, and they rush to see what she is pointing at out the window. After hours of her screaming, the people on the train can take no more, and they tie her up, gag her, and begin beating her to make her stop screaming about the fire. She breaks free from her restraints and periodically screams throughout the night, until everyone else on the train feels like they are about to go mad too.