Free On A Pale Horse by Piers Anthony

Then Zane realized that there had been violence; she had bruises and scrapes all over her body where flesh showed.
    Perhaps death would, in fact, be a boon to her. She was obviously living in misery.
    But the arrow did not point to the woman. It pointed to the crib on the far side of the room where a small baby lay huddled.
    A baby? How could he take a baby?
    Zane walked past the woman, who paid him no attention, and stood over the crib. The baby had scuffled off its inadequate blanket during the night and lay, exposed and damp, face down, its skin bluish. It was, he realized, about to suffer a crib death.
    But what of the fifty-fifty rule that governed his clients? Most people died and were separated from their souls without his direct help. Only those who so cluttered their souls with evil as to be in doubt of salvation required the personal service of Death. Almost by definition, a baby was innocent; therefore its freed soul should float blithely to Heaven. A baby was not yet, as Fate had quoted, the captain of its soul, and Heaven still lay about it.
    Yet there was no question this was his client. The baby was fading fast. It was time. Zane reached down and hooked out the small soul.
    The baby's mother, intent on her laborious dressing, never noticed. Zane walked past her, carrying the soul, and left the house. He felt ill.
    In the Death mobile, he used the stones to analyze the little soul. The pattern was strange, because it was not a pattern at all; the soul was uniformly gray. Experience had not yet caused it to be variegated.
    The verdict of the combined stones was neutral; the gem ball hovered in place like the moon it resembled, neither rising nor falling.
    How could this be? What evil had this little boy done? What evil could he have done, confined to his crib, completely dependent on his sick mother?
    Zane had no answer. He folded the soul neatly and put it in the bag.
    The Deathwatch was counting down yet again. Was there no end to this? When did he get some rest, some time to think things out?
    He knew the answer. Deaths occurred all the time, and the small percentage that required special attention continued, too. At some point he would have two difficult cases happen at the same moment, on opposite sides of the globe. What would he do then?
    Zane was beginning to understand how a person performing the office of Death could grow careless, as his predecessor had done. When things got rushed, comers had to be cut, or the job would not get done. What happened to a Death who got too far behind?
    He looked at the watch more carefully. It had three buttons on the side. This was a stopwatch, a chronograph, of course, though its timer did run backward. He had seen the type before. One button would be used to start and stop timing; another to zero the total; and the shorter middle one to set the regular time and calendar features when necessary.
    But this watch ran itself, magically, responding to input he did not know about. Maybe it had a direct line to Heaven or Hell or wherever the allocation of souls was determined. Fate probably had a hand in it, as she measured her threads. He didn't time events; events timed him. Why, then, were the extra buttons necessary? What did they control?
    He thought of punching a button. Then he hesitated; it could be dangerous to play with something he did not understand. Yet how else was he to learn? He had lived his life and almost died his death in an impetuous manner; he might as well be consistent.
    Experimentally, he punched the lowermost button. Nothing happened. It depressed and sprang back without any specific point of resistance. Had it been disconnected? Not necessarily; a good stopwatch was protected from an accidental punching of the wrong button, as might occur when someone was distracted by a close finish in a race and aimed for the STOP button without looking. This should be the zeroing control, operative only when there was a fixed time registered, as would be the case