David Logan deliberately sets fire to his own land, because it adjoins Harlan Granger's land. The lynch mob that has gathered to take T.J. disperses, as David hoped, when Harlan Granger orders them to go fight the fire. By this point in the novel, the Logans needed every cent from the sale of that cotton. Because they had organized a boycott of the Wallace store, and angered the Wallaces, as well as Granger, Mrs. Logan had been fired from her job, David (Mr. Logan) had been attacked, injured and was unable to return to his job, and the bank that held the family's mortgage had "called up the note," insisting the full amount due be paid immediately. David is counting on the fact that people will assume lightening from the thunderstorm started the fire and in the aftermath, T.J. will have a chance at a trial. In any case, he won't be lynched that night, due to David's creating this all-night distraction.