It had to be psychohistory. It would probably take him the rest of his life, tracking down the byways of this semichaotic technique, and he would end with it incomplete, leaving the task to others (to Amaryl, if that young man had not also worn himself out on the matter) and breaking his heart at the need to do that.

Yet it gave him a reason for living. He would live longer with the problem filling him from end to end-and that pleased her. Someday she would lose him, she knew, and she found that the thought afflicted her. It had not seemed it would at the start, when her task had been the simple one of protecting him for the sake of what he knew.

When had it become a matter of personal need? How could there be so personal a need? What was there about the man that caused her to feel uneasy when he was not in her sight, even when she knew he was safe so that the deeply ingrained orders within her were not called into action? His safety was all that she had been ordered to be concerned with. How did the rest intrude itself?

She had spoken of it to Demerzel long before, when the feeling had made itself unmistakable.

He had regarded her gravely and said, `'You are complex, Dors, and there are no simple answers. In my life there have been several individuals whose presence made it easier for me to think, pleasanter to make my responses. I have tried to judge the ease of my responses in their presence and the unease of my responses in their final absence to see whether I was the net gainer or loser. In the process, one thing became plain. The pleasantness of their company outweighed the regret of their passing. On the whole, then, it is better to experience what you experience now than not to."

She thought: Hari will someday leave a void, and each day that someday is closer, and I must not think of it.

It was to rid herself of the thought that she finally interrupted him. "What are you thinking of, Hari?"