One of the recurrent debates Eddie has with Roland over the course of the novel concerns the nature of a quest. For Roland, a quest is a spiritual journey, a single-minded pilgrimage that precludes everything else. It’s noble and pure by definition. For Eddie, on the other hand, one person’s quest can be another’s obsession, and an obsession can be selfish and dark. At one point, Eddie questions whether Roland’s hankering for the Dark Tower is like Eddie’s own need to use drugs. This suggests that Eddie may consider his need for drugs a quest. Eddie’s question is valid since it sheds light on an important fact: People can use a larger cause or the greater good as an excuse for morally questionable behavior. In the previous book, Roland sacrificed Jake, the boy whom he had come to love as his son, in exchange for clues about his quest. Roland’s decision seems hard to justify. Thus, the definition and demands of a quest are complex. Perhaps the biggest element that defines a quest is that it includes sacrifice on the part of the quester, a change that leads to self-growth.

In this sense, all three protagonists sacrifice something essential to them as the plot progresses.