By his day-slashed calendar he knew that tomorrow was the day. And for the first time he did not want to go. . . . Still, when the day broke in an incredible splash of sun, he gathered his things. (1941.17)
This is the day when many of the residents of the Bottom die, and the passage reminds us that our choices can have unpredictable consequences. Had Shadrack chosen to stay home that day, it's possible that the tunnel accident might never have happened. But when he chooses to fulfill his annual duty, his choice impacts the entire town.