As soon as the oxygen supply drops to the point where even three of us are in danger, Derec thought. That would probably happen sometime in the next couple of hours. That meant he would have to think of something fast if he wanted to save everyone.

But what could he possibly come up with that the robots wouldn’t have already considered and rejected? They would have been just as frantically trying to improve the odds even for three humans; yet they had come up with nothing.

Nothing that they could act upon, that is. Suddenly Derec smiled, for he saw the weak spot in the army of arguments aimed at Wolruf. They wouldn’t follow any course of action that would be riskier to the humans than spacing Wolruf, but that didn’t mean other courses of action didn’t exist. They just couldn’t act upon them, or even mention them to humans who might consider them the better alternative.

Nor would they allow the humans to discuss them in their presence, lest they become convinced to take an unacceptable risk

“All four of you, out,” Derec ordered suddenly. “Go back to the engine room. I’m not at all convinced that the recycler isn’t repairable. If all four of you work on it at once, then I’m sure you’ll come up with a solution we haven’t considered yet.”

Mandelbrot moved for the door immediately. Adam and Eve hesitated, and Adam said, “I do not see how our collaboration will make the unrepairable repairable.”

“Try it,” Derec said. “I order you to.” With a humanlike shrug, the robots moved after Mandelbrot.

Lucius, however, remained standing beside Avery. “I cannot follow Dr. Avery, s command to obey his every whim if I leave his presence,” he said.

“I release you,” Avery said. “Go with the others.”

“I echo Adam’s reservation. The recycler is damaged beyond repair.”

Avery thundered, “Damn it, you’ve been questioning every order you can this whole trip, and I want it stopped! When a human tells you to do something, you do it. Understand?”

“I understand your words, but not the reason. If I obey blindly, might I not inadvertently violate your true intent if your order was less than precise? I can better judge how to act if I know the reason the order is given.”

“You’re not supposed to think; you’re supposed to act. It’s my job to see that the order is clear. You can assume, if it makes things any easier for you, that I know what I’m doing when I give it, but your understanding is not required. In some cases-” this with a sidelong glance at Derec “-it’s not even wanted. It’s enough that I am human and I give you an order. Clear now?”

“I must think about this further.”

“Well, think about it in the engine room. Now go.”

Lucius followed the other three robots without another word. Avery waited until the door had closed behind them, then said, “Okay, I know what you’re trying to do. What kind of hare-brained scheme have you come up with?”

Derec spread his hands. “I haven’t, but there has to be one. The robots are thinking no-risk solutions. I reject that if it means sacrificing Wolruf.”

“Thank ‘u.”

“So now we think of low-risk solutions. And if we don’t come up with something, we think of medium-risk solutions. And if that-”

“We get the picture,” Ariel cut in. “So what’s risky and will get us some more air?”

Derec hmmmed in thought. “Electrolyze something else? There’s got to be oxygen bound up in something besides water.”

“As well as poisonous gasses,” Avery said. “Without the recycler to clean out the unwanted products, we’d die even faster than by suffocation. No, that goes in the extremely risky category.”

“How about suspended animation?” Ariel asked. “Freeze one of us, and revive him when we get to Ceremya.”

“Again, extremely risky. The odds of survival are barely twenty percent under the best of conditions. Here, we might achieve ten percent. That’s not what I call a solution. I would, however, allow Wolruf to try it as an alternative to certain death.”

“Very generous of ‘u,” Wolruf growled, “but there’s a better solution.”

“What is it?” Derec asked eagerly.

“Shorten the trip.”

“Shorten how? We still-oh! Do it all in one jump.”

“We’ve got three jumps left,” protested Avery. “You’re suggesting we triple our distance? I’d call that an extreme risk as well.”

Wolruf shook her furry head. “Not triple. Cut it to two jumps, each one and a ‘alf times normal. Seven and a ‘alf light-years instead of five. Save a day and a ‘alf coasting time between jump points. Not that dangerous; trader ships do it all the time.”

“There may not be a jump point exactly in between. “

“So we go eight and seven, or nine and six. Still not risky.”

“How risky is not risky? Let’s put some numbers on it. How many trader ships get into trouble with long jumps?”

“Almost nobody gets ‘urt from it. Maybe one in twenty goes astray, has to spend extra time getting’ ome.”

“Which would kill all of us.”

Derec said to Avery,” A minute ago you said a ten percent chance of success wasn’t good enough for you. Fine, I’ll grant that. But one in twenty odds is ninety-five percent in our favor! That’s an acceptable risk.”

“I agree,” said Ariel.

Avery pursed his lips in concentration, considering it. Now he drummed his fingers 01.1 the tabletop.

“Now’s the time to decide whether you’re cured or not,” Ariel added. “Can you make a personal sacrifice for someone else or do you still think only of yourself?”

“Your psychology is charmingly simplistic,” Avery said. He drummed a moment longer. “But unfortunately, it’s still correct. The risk seems slight. common decency seems to dictate that we take it.”

Wolruf let out a long-held breath.

“You’d better get to it,” Derec told her. “The robots are bound to realize what we’re doing behind their backs before long, and as soon as they do, they’re going to try to stop you.”

“I’m going,” Wolruf said, rising from her chair and rushing for the control room.

They were lucky the ship had been coasting all day toward a jump point, lucky they hadn’t already gone through it. If they had had to wait another day to carry out their plan, they would never have gotten away with it. As it was, Wolruf had only been gone a few minutes before the robots burst back into the room, all four cycling together through the mutable airlock that had once been a simple door.

Seeing the empty chair where Wolruf had been, Lucius became a blur of motion streaking toward the control room. “No!” he shouted. “You must not risk-”

There was a faint twisting sensation as every atom in the ship was tom asunder and rebuilt light-years away.

“Too late,” Derec said.

The robot skidded to a confused stop. “You…tricked us,” Lucius accused.

Avery let out the most sincere laugh Derec had ever heard him laugh. It went on and on in great peals of mirth, and when he finally calmed down enough to speak, he said, “Get used to it. To quote a famous dead scientist, ‘Old age and treachery will always overcome youth and innocence.”