In addition to the previous reviewer's comments, Keller was sexually molested by a firefighter between the ages of 12 and 19. This explains quite a lot about his motives and reasoning. This doesn't excuse him but does give us a lot of insight as to why he resorted to fire as a means of regaining "control" of his surroundings. Most arsonists use the destruction of fire as a means of asserting control that they lost at some point in their lives. Componding the fact that his abuser was employed to fight fire it seems even more "logical" that an individual whose emotional stability has been distorted would resort to setting fires. Keller was the one who was in control of when, how and where the destruction would occur. No one could figure out who he was and therefor couldn't stop him leaving him in total control of the situation. Though these kinds of individuals can't be excused for their actions, their psychology makes for a very intriguing story.
