Infinite Jest is a black comic novel that explores themes of American addiction: to drugs, alcohol, entertainment, technology, etc.
In the chapter we excerpted, a thief, Don Gately, as part of his rehabilitation, begins to attend meetings of Alcoholics Anonymous, and starts to understand it as a way of life that somehow, mysteriously, melts away the addictions of those who strictly follow its program.
But don't worry, it--like the rest of the novel--is never earnest or preachy. If David Wallace and Quentin Tarantino had a "sick sense of humor" contest, Wallace would win.