Both The Gunslinger and The Drawing of the Three have a relatively small cast of characters. The central figure in both books is Roland, the last gunslinger.

He is a quester who appears to have emerged from a western movie but who seems to come from a post-apocalyptic future. Because he saw the changes in the world—from the electric lights of civilization to the darkness of a wasteland—he has a compulsion to seek the Dark Tower and to restore the world. He is prepared for this task by his training as a gunslinger. As an efficient killer, he is practical, intelligent and tough—tough enough to make callous decisions, which could lead some readers to think he is slightly mad or satanic.

In The Gunslinger, the other major character is the Man in Black. Dressed like a priest in a black cassock and...