In William Faulkner's As I Lay Dying it shows Darl's change from sanity to insanity as the novel unfolds. No one knows of this change until it is to late for them or Darl to do anything. Darl finds that his hold on reality starts to loosen as he figures out to himself that his mother does not exist if she is dead. Darl to others was always regarded as strange. "Nevertheless, he was regarded by others as strange"; as Cora Tull says, he was "the one that folks says is queer, lazy, pottering about the place no better than Anse."
Darl unlike others in his family showed no motivation to make the trip to Jefferson with his mom's corpse and was little to no help to his family on their journey.
There are many events on the Bundren family's journey to Jefferson leading to Darl's downfall where he is eventually sent to a mental asylum in Jackson. The first of these on going events is when the family is trying to cross the flooded Yoknapatawpha River. Darl was useless in trying to save Addies coffin or the wagon from the flood waters. Darl throughout the novel shows little emotion toward anyone or anything including his family He is very behind the scenes and quiet about things he sees and knows such as Darl knew about Dewey Dell being pregnant or Jewel being illegitimate. "Darl exhibited signs throughout the novel of an ego at odds with itself; lacking a definitive way of identifying himself, he demonstrated in his narratives detailed descriptions of events but seldom did he reveal any emotional attachment to his subjects."
The second of events leading to Darl's downfall is when his family reaches a place to stay further in the novel. They sought shelter at a man Gillespie's barn where they were going to stay the night on there way to Jefferson. But then tragedy strikes when the barn catches fire and burning to the ground Addies corpse is still inside is saved. This event happened because...