He tried to explain. "We Voidtreckers, if we stay on the train long, become used to the train's habit of going to worlds that are in trouble and dispatching us to deal with the problems, and we find something in this that satisfies us. Many of us are people who were already deeply concerned with helping others. I am one such. We don't get rewards for helping, except for the reward of knowing that there are worlds that are better off for our having been there."