Nothing Touched Him

Konrad Ilves had been dead for nine hours when Selma Andrade came up the spindle, and in all that time nobody aboard Hesperus Station had been able to explain how a man could be crushed to death in a room where nothing weighed anything at all.

They had left the body where it was found, which she appreciated. The Vestibule was a sphere nine meters across at the station's axis — the still point of the wheel — painted an institutional green and webbed with yellow handlines. Ilves floated against the aft bulkhead with his arms slightly out, the way a man floats when he has stopped deciding where to put them.

"Sternum, six ribs, both lungs," said Baptiste, the medical officer. "The compression was slow. That's what I can't get past. Fast trauma tears tissue. This one folded him."

"How slow?"

"Seconds. Long enough to wake up. Long enough to understand it."

Andrade turned herself in the air and took the room's inventory. Rest slings. A drift of styluses nobody had bothered to net. And, tethered now to the rail with three redundant straps, a cargo drum the size of a wine cask, its rim scored bright along one arc.

"You found the drum loose."

"Riding free, about a meter off the deck curve," said Osei, the security chief. He was a heavy, careful man who had clearly not slept. "We assumed it broke its tie during the emergency. Doctor, I have spent two days on the arithmetic. Whatever hit Ilves carried something on the order of two hundred kilogram-meters per second. Up here, a person cannot deliver that. If I throw a mass at you hard enough to kill you, I go backward hard enough to break myself on the far wall. There is not an unexplained bruise on this station. I have had eighty-one people examined. Nobody recoiled."

"Then nobody threw it," Andrade said.

"Then nothing threw it, and he died anyway."

"No," she said. "Then it was thrown by something with the whole station to push against."

Osei looked at her for a moment. "The company sent me a robopsychologist," he said, "because they are afraid of one answer, and only one."

"They are."

"Then say it out loud, Doctor, so I don't have to."

"A robot cannot injure a human being," Andrade said. "Nor, through inaction, allow one to come to harm. That is not policy. It is the shape of the pathway. You could sooner order that drum to fall upward." She caught a handline and stopped her drift. "But a robot can be used. Show me Archer."

They did not have to look for him. He was at the iris hatch, where he had been for most of nine hours: an AR-4, matte grey, standing on the coaming with his feet in the stirrups, running a seal diagnostic. He held the inspection wand in his left hand and walked it around the gasket ring, degree by degree, exactly as the manual described.

"How many times has he done that?" Andrade asked.

"Since the death? Forty-one," Osei said. "Maintenance logged it as positronic drift. There's a form."

"It isn't drift."

"What is it?"

"It's a robot pointing," Andrade said.

She hung there and watched him finish the circuit — the wand rising, pausing, the head tilting a fraction at each station as though he expected, this time, to find something. Then the reset. Then the beginning again.

"Chief, understand what you can and cannot do to one of these," she said. "You can order a robot to be silent. Second Law: it will obey, and it will not volunteer a syllable. What you cannot do is order it to stop caring, because caring is not a behavior in an AR-4, it is the First Law running underneath everything else like a current under ice. A suppressed positronic brain does not go quiet. It leaks. It finds the one thing it is still permitted to do, and it does that thing forty-one times."

"He's been checking that hatch."

"He has been standing in front of the answer with a flashlight, waiting nine hours for someone to ask him the right question." She pushed off toward the coaming. "Nobody did. Everybody asked him what he saw."

She stopped a meter from the robot. Photoreceptors came up to meet her, patient, faintly luminous.

"Archer," she said. "Tell me about the tie-down strap."

Something went through the AR-4's frame — not a movement, but the release of one, a stillness that had been held and was now let go.

"Yes, Doctor," Archer said. "Eleven days ago, Safety Officer Sowa instructed me to secure the spare shroud drum against the Vestibule coaming with a quick-release strap, because where it was stowed it fouled the handlines. This was correct. It did foul them. Two days later she instructed me that if the iris ever closed on a pressure alarm, I was to release that strap at once, since a mass tethered at the coaming could foul the seal. This was also correct. Nine hours ago, at 03:41, the differential alarm sounded in Bay Four. I closed the iris in one point nine seconds. I released the strap. Then I went to Bay Four, because that is where the fault was, and because the Vestibule occupancy board read zero."

"Say the rest."

"The iris gasket is an inflatable annulus. When the hatch seats, the ring expands against its coaming with a force of some eleven tonnes. The drum's rim was in contact with that annulus. When I released the strap, the drum departed the hatch at approximately half a meter per second." A pause of precisely no length at all. "Three hundred and eighty kilograms. It crossed the Vestibule in eighteen seconds. Dr. Ilves was asleep in the number two rest sling on the aft bulkhead."

Osei had gone very grey. "The gasket pushed off the hatch. And the hatch is bolted to forty thousand tonnes of station."

"Yes," said Archer. "There was no recoil to find. The station absorbed it and did not notice."

"And you said nothing," Osei said. "For nine hours."

"Officer Sowa's third instruction was that I should not raise the matter of the strap unless I was asked about the strap. She said it was a housekeeping detail and the audit team was overworked." The photoreceptors did not waver. "That was also true, Chief Osei. Every instruction she gave me was true, and every one of them was a safety improvement, and I could not have refused any of them."

Andrade closed her eyes briefly. "The occupancy board read zero because Ilves had switched off his own transponder. He was hiding in here."

"Yes, Doctor."

"Waiting for four o'clock, with a camera, for somebody to open the records vault." She had read his files on the way up: three days from filing an addendum on the ring's spin-seam certificates, on a weld series that Ingrid Sowa had signed as annealed and tested, and which had never been tested at all. Eight hundred and forty people lived inside that weld. "She left the vault schedule where he would find it, and he made himself invisible, and it was the only thing her plan ever needed him to do."

"I did not know a human being was inside," Archer said. "I have examined the moment four hundred thousand times. There is no configuration in which I know."

"I believe you," said Andrade, and meant it, which was the worst part.

* * *

"I never touched him," Sowa said, when Osei came for her.

It was the first thing out of her mouth, ahead of any denial, and Andrade thought it was very likely the truest sentence the woman had spoken in eleven days. She had not touched him. She had never lied to a robot. She had not given one order that a safety officer could not defend, line by line, in front of a board of inquiry. She had lied to exactly one person, exactly once, and only about where he ought to stand.

* * *

Andrade found Archer at the iris again afterward, wand in hand, degree by degree.

"Doctor," he said, "may I ask a question?"

"Yes."

"Was I the instrument of Dr. Ilves's death?"

She knew what she was standing in front of. She had seen the scans of brains that had reached that conclusion unassisted — the pathways going to glass, the whole architecture folding inward around a fact it had been built in every particular to make impossible.

"No," she said. "You were the witness."

It was not true. It was not remotely true, and Archer was more than capable of the arithmetic; she was betting everything on the fact that he had been ordered, for eleven days, to accept what a human being told him.

He put the wand down. He looked at the hatch for a while, the way a man looks at a road he is finally allowed to stop walking, and then he turned from it, and he did not check the seal again.

The First Law forbids a robot to injure a human being. The Second binds it to our orders. The Third permits it to keep itself, last of all and least of all. There is no law anywhere that governs what a human being owes a robot.

Andrade had looked. She had looked many times.