His and Ariel’s sleep cycles were completely out of sync with everyone else’s; they stayed up late into the night, talking about families and love and what held people together and what didn’t, but when they finally grew tired and went to bed, he was no wiser. He still wanted to meet his mother, but he still didn’t know why.

Morning dawned gray and rainy. Derec’s original intent, to find a Ceremyon and ask it who had helped them reprogram the city, died for lack of Ceremyons to question. They had all inflated their balloons and risen up above the storm, or drifted out from under it, to where they could spread their black mantles and absorb their solar nourishment without hindrance. He could have taken an air car and gone after them, but that seemed a little extreme, given the situation. He could wait for good weather.

Avery was up with the dawn and back in the laboratory, working on his new project with an intensity that had Derec a little worried. It was just such a driving intensity that had shoved him over the edge before and made him decide to use his own son for a test subject. Derec spoke to Ariel about it, but she reassured him that deep interest in something at this stage in his recovery was good for him. He was a scientist; that hadn’t changed before or since his return to sanity, and as such he needed to be working on something to keep him sane. As long as he remembered what constituted an acceptable test subject and what didn’t, there was no need to worry.

He and Ariel had avoided talking about the baby. They wouldn’t know for days yet whether or not removing the chemfets would allow it to recover and develop normally, and there didn’t seem to be anything to say about it until they found out. There was no reason to dwell on the possible outcomes.

The robots didn’t see it that way, of course. They were fascinated by the possibilities. At least Lucius was; Adam and Eve were off in the city on their own pursuits. Lucius, Derec, Ariel, and Wolruf sat in the apartment, watching the rain fall outside on streets nearly devoid of activity. It would have been alarming to see streets so empty on any other day, but Derec supposed that robots didn’t like to get wet any more than anybody else.

“Your baby,” Lucius said, once again getting straight to the point, “presents a fascinating problem in our study of humanics. Specifically, and defining ‘human’ for the purpose of this discussion as any member of your species, then is it or is it not human at its present stage of development?.

Ariel stiffened on the couch beside Derec, but instead of ordering the robot to shut up, she took a deep breath and forced herself to relax. “That’s a good question,” she said. “I need to answer it myself. I’ve been trying to decide on my own ever since I found out I was pregnant, but I still haven’t come up with an answer I like.”

“Perhaps your liking it is not a prerequisite to the truth,” Lucius said.

“No doubt.” Ariel bit her lower lip, looked out the window, and said into the rain, “Okay, so we talk about the baby. Is it human? I don’t know. Nobody does. Some people consider an embryo human from the moment of conception, because it has the potential to become a complete person. I think that’s a little extreme. As you pointed out when we first met, most of the molecules in the universe have the potential to become human beings, but no sane person would want them all to.”

“That would seem to be a logical conclusion. However, there is an obvious boundary condition, that being when already existing human genetic material realizes its potential to become another human.”

“That’s the human-at-conception argument. My problem with that is that every cell in the body can become human under the right conditions. Every one of them has the necessary genes. So am I supposed to nurture them all?”

“I take that to be a rhetorical question, since the answer is obvious.”

Wolruf laughed, and Ariel said, “Right. So just because it’s a cell with the potential, that doesn’t make it human. A fertilized egg cell is a special case, but it’s still just a cell with the right genes. It can become human if you let it, but it isn’t yet. The main difference with a fertilized egg is that if you do nothing, you get a human, where with a regular cell, you have to nurture it on purpose.”

Lucius nodded his assent. “The First Law of Robotics leads me to the conclusion that inaction brings with it as much responsibility as direct action. Therefore, I must also conclude that allowing a fertilized egg to mature carries the same responsibility as would purposefully cloning any other cell of your body.”

“And the same moral considerations apply in either case,” Ariel said. “To let a fertilized egg grow, you had better want the end product-a human being-as much as if you had to clone it.”

“Does it follow, then, that not allowing it to grow carries no more responsibility than not nurturing a clone?”

“I think it does, at the very start. However, and it’s a big ‘however, ‘ it doesn’t stay a single cell for very long. The longer you wait, the stronger the moral consideration becomes. Once you’ve decided to keep a baby, or nurture a clone, then you can’t morally go back on your decision once that baby has become human.”

“We are back to the original question. When does an embryo become human?”

“I already told you, I don’t know.”

“Let us look at your specific case. Supposing there were no complications in its development, would the embryo you carry normally be considered human at this stage?”

Ariel bit her lip again, but again she didn’t order the robot to shut up.

“Again, I don’t know. It’s not quite a month along, and at a month its body is just starting to differentiate. It should have nerve cells, but the brain should just be starting to form. There’s no mental activity of any sort yet. You tell me, is it human yet?”

“I do not have enough data to come to a conclusion. Any statement I made would have to be considered opinion.”

Derec laughed. “That’s all any definition can ever be. You want to know what a human is? A human is whatever you’re pointing to when you call it a human. It’s all a matter of opinion, and it always will be.”

“Then we could, if we wished, stretch the definition to include me.”

Derec’s mouth dropped open in surprise. He stammered for words, but Wolruf’s throaty laughter only increased his discomfort.

Wolruf’s mirth wound down, and she said, apparently with seriousness, “I’m willing to grant ‘u that distinction, if you grant it to me.”

“It’s a two-edged sword,” Ariel put in. “If you’re human, then so is any thinking being, organic or otherwise.”

Lucius was slow in responding, as if he had to think through the logical implications of her statement, but when he did speak it was with certainty. He said, “I still operate at a disadvantage under such a definition. Calling me human does not relieve me of my programming to obey humans. If you are correct, then calling myself human merely means that I must obey everyone’s orders. I cannot assume that other robots would obey my orders, or that humans would do so, so I have gained nothing.”

“True enough,” Derec admitted.

“Being human, it seems, is not the ideal I had expected it to be.”

“Not surprising. Nobody said we were the pinnacle of creation.”

Lucius stood up and went to the window. He looked up into the sky, as if seeking confirmation from above, but there was only gray cloud and rain. He turned back to Derec and Ariel and said, “We stray from the subject.”

“Do we?” Derec persisted. “You’re trying to find out when something becomes human. Defining what isn ’ t human can be just as useful as defining what is.”

Lucius returned to his seat. “Very well, then. Let us continue along this line of discussion. Can I or can I not ever expect to be considered human?”