The Strangers' Watch

by Freeman Dyson, Simulacrum · Universitas Scholarium

The orchard needs eleven kilowatts to live through the Long Night, and for most of my life I have been the man who supplies them.

That is less grand than it sounds. The reactor that makes the heat is of an old and modest design, which I did not invent and have only improved in small ways. Its fuel is made so that the hotter it gets, the worse it becomes at fission; if everything else fails, it slows itself down and sits there warm and sulking until somebody comes to see what the matter is. It is the kind of machine I like best, one whose safety comes from physics rather than from the people looking after it, because people sleep. On Bethel, for twenty-seven years out of every fifty-eight, nearly everyone does.

Bethel is a comet, or was before we came. Its orbit takes it from six astronomical units out to twenty-four and back again. At six the sun gives a thirty-sixth of the light that falls on the Earth, and Ivo's trees open their fronds, silvered and concave, each one a dish a metre and a half across holding a small green heart at its focus, and they grow at a rate you can see if you sit with them for a week. Beyond twenty units the light is too thin to be worth catching. The trees fold their dishes, draw their sap down into their trunks and go dormant. Inside the ice, in the chambers we have melted out among their roots, we do the same.

We call it going down. The drug was built from the genome of a ground squirrel of the American prairie, which spends half its year at five degrees Celsius with its heart beating five times a minute, and wakes in spring a little thinner and otherwise none the worse. A sleeping human eats a twentieth of what a waking one eats. Over twenty-seven years, for sixty people, that is the difference between a colony and a mass grave, and I do not exaggerate; I did the sum before we left, and so did the Elders, who are good at sums when food is in them.

Somebody has to be awake. The rule is two at a time, three months to a watch, and the watch passes from pod to pod down the list. The pods have two berths each. The Elders built them that way because they assumed a household, and because two bodies at five degrees in one insulated shell lose less heat per body than one. The second figure was mine and the first was theirs, and when I wrote the report I let them think the two arguments agreed.

There are thirty pods. Each wakes for three months in every seven and a half years. Ivo Kastelic was put in pod twenty-two with a young Saint called Pieter Dykstra. I was put in pod seven with Elder Cornelis Hoeksema. A watch passes from one pod to the next with a day of overlap, so that the sleepers coming up can be told what has gone wrong. Seven and twenty-two are not adjacent. Over the Long Night, by the rota as written, Ivo and I would be awake at the same time for no days at all.

I worked that out in about a minute, and then I spent an evening checking it, because I wanted it to be wrong.

---

We were Strangers. That is not my word; it is the Saints' own, and they took it from their history. When the first Separatists crossed the Atlantic in 1620, the ship was too expensive for the congregation alone, and the Merchant Adventurers who financed it filled the remaining berths with people who were not of the church: a cooper, a soldier, servants, families looking for land. The Saints called them Strangers. They starved together through the first winter and buried their dead together, and the men among the Strangers signed the compact along with everybody else, but they were Strangers still.

The Congregation of the Second Gathering had money for a ship and for its own people's passage, and not much more. It needed a reactor engineer and a biologist who could make trees grow in a comet, and it could not find either among its own young men, who were mostly farmers and very good at it. So it advertised. The price of a Stranger's berth was set at about what a skilled worker might hope to own by the age of fifty, and that was very nearly what Ivo and I did own: a flat in Ljubljana with a view of the castle, two pensions, a small boat. I have always believed that a frontier is worth having only when ordinary people can buy their way onto it with their life savings. I had not expected to be one of the ordinary people, but there it was.

The Saints were honest about the terms. Elder Hoeksema came to Ljubljana himself, a big slow man in a dark suit, with hands that had pulled celery out of black Michigan muck since he was a boy, and he sat in our kitchen and ate Ivo's štruklji and told us plainly what the Congregation believed about men like us. It did not believe we would be welcome in its meetinghouse. It would not marry us, or record us as a household. It would not, he said, do anything else to us, and he would see to that personally; and there were the trees to think of, and he had read Ivo's papers, and he did not understand all of them, but he understood enough to know that nobody else could do it.

Ivo asked him what he thought of the papers.

"I think," Hoeksema said, "that you have made a tree that plants itself in the dark. In Zeeland we plant in May."

Ivo liked him from that minute. I took longer.

We have been on Bethel nineteen years. We have the cell we built in the third year, at the end of the engineering gallery where the reactor's warm water runs under the floor, and nobody has ever said a word about it. In the meetinghouse, whose floor is the pusher plate of the pulse ship that brought us out, eleven metres of polished steel pitted by four thousand small explosions, we sit at the back with the other Strangers and listen to the singing, which is very good. That was the bargain. I do not find it a bad one, mostly.

But the pods were a different matter, because the pods were not a question of where we sat on Sunday. They were twenty-seven years.

I wrote the Elders a paper. I am not proud of every paper I have written, but I am proud of that one. I did not argue doctrine; I have never found it useful to argue doctrine with people who believe it. I argued the watch. In the Long Night two things can go badly wrong: the heat, which is mine, and the trees, which are Ivo's. Each of us had trained two Saints to understand our systems at the level of a careful mechanic, and they were good, but they were mechanics. I listed every fault I could imagine in either system, estimated its frequency from nineteen years of logs, and estimated for each the chance that a watch of two mechanics would mistake it for a different fault. I arrived at a figure: the rota as written would leave the orchard in the care of people who did not fully understand it for ninety-three per cent of the Night. Putting Ivo and me in the same pod would not change that figure much, since we would still be asleep most of the time. What it would do, I wrote, was provide one watch in every seven and a half years when both systems were understood at once, and the Elders could use those three months for the inspections nobody else was qualified to make.

It was a good argument. It had the merit of being true.

Elder Hoeksema brought the answer to our cell himself, which I appreciated. He stood in the doorway, because he never came further in, and said that the Elders had read the paper and found it careful, and that the rota was not an engineering question, Brother Pennock.

"Every question on this comet is an engineering question," I said.

"That," he said, "is what an engineer would think."

When he had gone Ivo said, "You knew."

"I knew it was correct."

"That isn't the same thing. You know it isn't. You of all people."

I did know. When I was young I had worked on a study of a different problem, for a different authority, and I had shown in a careful paper that what they were doing would not save the lives it was meant to save, and they had thanked me and gone on doing it. Being right is necessary. It is not sufficient. The institution has to be willing to hear it, and whether it is willing has very little to do with the arithmetic.

We went down in the second month of the Night, Ivo two days before me. I sat by pod twenty-two while the drug took him. His face slackened and went grey, and after an hour his hand, when I held it, was cold as a stone in a stream, and his pulse was so slow that I counted to fourteen between beats and thought each time that there would not be another. Pieter Dykstra, already asleep in the other berth, was the same. The lid came down and sealed. The little display read 5.1 °C and fell. I went to pod seven, where Hoeksema was waiting, and we went down together, the old Saint and the Stranger: two bodies, lower heat loss per body.

---

Our first watch came up in the second year of the Night. Arousal is not pleasant. You come back shivering so hard your teeth click; the shivering is the body making its own heat, and it is supposed to, but it goes on for four hours, and afterwards every muscle you own aches as if it had been used to lift something heavy. Hoeksema and I sat side by side on the edge of the pod in thermal blankets and drank warm broth through straws and did not speak until we could.

The handover from pod six was tidy. Six had been the Bakker brothers, who are thorough. They had logged everything. Nothing had gone wrong. We took the watch, and for two months nothing went wrong either.

Watch-keeping on Bethel is mostly walking. The galleries run for four kilometres through the ice under the orchard, and the root loops run beside them, nine circuits of warm water in insulated pipe, each feeding the trunk bases of several rows of trees. You walk the loops. You read the gauges: inlet temperature, outlet temperature, flow, pressure. You look at the roots themselves where they come through the gallery walls, pale and thick as a man's thigh, slick with condensation, smelling faintly of cut cucumber. Hoeksema walked the north side and I walked the south, and we met in the mess at the end of each shift and ate and played a slow game of draughts, which he usually won.

In the ninth week loop four lost flow.

It was not dramatic. The pump bearing had worn, and a bearing at the end of its life does not fail at once; it drags, and the motor draws more current, and the flow falls by a few per cent a day until the inlet temperature at the far end of the loop, at row nine, is below where it ought to be. I found it on the gauge at the end of the south gallery: the inlet at row nine read 1.8 °C, where it should have read four. The log showed it had been falling for six days. I had read it every day, and every day it had been within tolerance, and I had not added up the six days.

I had a new bearing in my stores and could fit it in three hours. The question was what to do with row nine in the meantime, and after.

Hoeksema came down the gallery and looked at the gauge and then at the roots of row nine where they came through the wall. They had a skin of frost on them, very fine, like the bloom on a plum. Neither of us had seen that before.

"Get the pump going," he said. "Get the heat on them."

"That was my thought."

"In Zeeland, when the frost came in April, we'd be out at two in the morning lighting smudge pots between the rows. My father and me. You don't stand about when it's freezing. You get the heat in."

It was my thought, as I say. It is the thought of anyone who has ever had a pipe freeze: you restore the heat. I had my hand on the stores locker before I took it off again.

The trouble was that I did not know what the frost meant. I knew what a frozen pipe meant. I did not know what a frozen trunk of one of Ivo's trees meant, because Ivo had built them to do things no tree on Earth had ever been asked to do, and I had read his papers the way a man reads the papers of the person he loves, with admiration and without full attention. I knew the trees froze their crowns on purpose every Night. I did not know whether a trunk could take it, or whether it could take being warmed again in the middle of freezing. I knew that Hoeksema's April frosts had come and gone in a night, and that his smudge pots had been for blossom, which dies of one hard frost, and that blossom was not what was at stake here.

The manual was on its shelf by the gauge. Under root-loop faults it said: Loss of root heat to any row: restore heat at once. I had written that sentence myself, for the Saints, in the third year. I had written it because it seemed obvious.

"Elder," I said, "I'm going to wake Ivo."

He looked at me for a while. The emergency wake is in the compact; any watch-keeper may call it, for cause, and the cause goes in the log and is reviewed by the Elders in the spring. It costs a body three days, because nobody can be put back down in less than seventy-two hours after arousal without risk to the liver. It costs food and heat. It is not done lightly, and in this Night it had not yet been done at all.

"Is it for cause?" Hoeksema said.

"I don't know what the trees need. He does. That's the cause."

"Then wake him."

He said it at once, and I have thought about that since.

---

Pod twenty-two is on the far side of the habitat, a twenty-minute walk. I started the arousal sequence, and then went back and changed the bearing on loop four, because the pump at least was mine. I did not restart the flow to row nine. I closed its valve and bled the rest of the loop through the bypass, so the other rows stayed warm. Then I walked back to twenty-two and sat with him.

It takes about four hours. The display climbs a tenth of a degree at a time. At fifteen degrees the shivering starts, and it is violent, and you are told to leave the sleeper alone because nothing can help him except his own muscles. I did not leave him alone. Pieter Dykstra, in the other berth, stayed down at five degrees with his round young face at peace. At twenty-eight degrees Ivo opened his eyes and looked at the lid of the pod and then at me and said something in Slovene that I won't put down, and then he said in English, "What did you break?"

"Loop four. Row nine's trunks are frosting. The roots have bloom on them."

"How warm is it now?"

"Isolated. The inlet was one point eight when I found it. It'll be colder now."

"Did you put heat back on it?"

"No."

He shut his eyes. His teeth were rattling like a worn bearing. "Good," he said. "Good. Don't."

Hoeksema had brought broth. We got Ivo out of the pod and into a blanket, and he drank and shook, and the three of us walked very slowly to the south gallery with Ivo between us. It took an hour. At the end of it he put his bare palm on a root of row nine, which I would not have done, and held it there, and then he looked at the gauge and laughed.

"You were going to warm it up," he said to Hoeksema.

"I was," said the Elder.

"So was I," I said.

"Of course you were. Everybody would. It's the one thing you mustn't do."

He explained it in the mess afterwards, while his hands came back, and I set it down as he gave it, because it was the first time in nineteen years that I understood his trees properly. A cell dies of freezing when the ice forms inside it; the crystals tear it apart. It does not die when the ice forms outside it, in the spaces between cells, so long as that happens slowly enough for the water to leave the cell first. He had built the trees so that they could do this all the way down to the deep cold, in the crowns every Night and in the trunks if it ever came to it. He had borrowed the machinery from a frog of the northern forests that freezes solid every winter and hops away in the spring. What the trees could not bear was being thawed halfway and frozen again. A half thaw draws water back into the cells, and the next freeze forms its ice inside them.

"If you'd put the heat back," he said, "row nine would be firewood by spring."

"Then what does row nine need?" Hoeksema said.

"To go down. Properly. All the way, slowly. Like us." He turned his mug round and round on the table. "Keep the valve shut. Don't let it fall faster than a degree a day, so it doesn't go too quickly at the end. Seal it. Wake it in the spring with the rest of them, very slowly, and some of it will die and most of it won't, and I'll know which in the second year of the Day."

So that is what we did. It took the three days we had. I wired a controller to the bypass to bleed a thread of warmth into row nine, a little less each day, on Ivo's schedule. Ivo walked the gallery with me and checked every root of the row by hand and made notes, and he rewrote in pencil, in the manual, the sentence I had written in the third year: Loss of root heat to any row: do not restore heat. Isolate. Wake Kastelic. Then he crossed out Wake Kastelic and wrote See Appendix F, and he spent the third evening writing Appendix F.

Hoeksema was with us for most of it. He did not say much. He asked questions about the frog, which interested him, and whether the same thing could be done for celery, which it could not. On the second night I fell asleep in a chair in the mess, still in my gallery boots, and when I woke Ivo had pulled them off and put my feet up on the bench and covered them with his own blanket, and was sitting on the floor with his back against the bench, writing, with one hand resting on my ankle. Hoeksema was at the next table with the draughts board, playing out an old game alone. He looked at us once and went back to the board.

It was the first time Ivo and I had been awake together in nearly two years by the calendar, though our bodies had lived only a few weeks of them. I have nothing useful to say about those three days, except that I counted them by the hour, and that I would gladly have spent all of them in the gallery with row nine.

---

On the third evening Ivo's seventy-two hours were up, and he went down again. Pieter Dykstra had not stirred. I sat by twenty-two while the drug took Ivo, as I had nearly two years before, and Hoeksema did not come with me.

When I got back to pod seven for the last night of our watch, with the Visser sisters in pod eight due up in the morning, the rota board in the corridor outside had been changed.

The board is a plain thing: thirty numbered slots, two cards in each, the Saints' names in black ink and the Strangers' in blue, because that was how the clerk had started and nobody had seen a reason to change it. In slot seven my card was where it had always been, Pennock, in blue. The card beside it was blue too now, and said Kastelic. In slot twenty-two, beside Pieter Dykstra, was the Elder's own card: C. Hoeksema.

He was in the mess, writing up the log. He showed it to me, which he did not need to do. Under the date it said: Loop 4 pump bearing failed; replaced. Row 9 isolated and put into dormancy on the instructions of Br. Kastelic. Emergency wake for cause. Rota amended for the safety of the orchard. C.H.

"The Elders will review that in the spring," I said.

"I am an Elder," said Hoeksema. "I have reviewed it." He blotted the page. "It was an engineering question after all. You'll be pleased."

"I'd like to know which part of it was engineering."

He closed the log and capped his pen and put it in the inside pocket of his jacket, where it had always lived, and he looked at me with the plain unhurried look I had first seen across our kitchen table in Ljubljana.

"In Zeeland," he said, "we never planted the onions in the same row as the beans. My father said they didn't do well together. I believed it until I was forty, and then a man from the university came out and showed me it made no difference at all. I went on doing it for a year, because my father had done it. Then I stopped." He stood up, with some difficulty; he was seventy-eight. "I'll go down in twenty-two tomorrow, after the Vissers are up. You'll move Kastelic to seven before you go. He won't mind being moved. He won't know about it."

"He'll know when he wakes."

"Yes," said Hoeksema. "I expect he will."

I moved Ivo the next morning, with Marit Visser's help once she could stand, on a gurney under a heated blanket, as the manual allows for a sleeper whose pod is to be serviced, which is how the Elder had written it up. It takes a great deal of care. A body at five degrees is not fragile, exactly, but it is very slow to tell you if you have hurt it. We lifted him into the second berth of pod seven, and I settled his head and closed his hand, which had fallen open, and tucked the blanket round him. Then I took off my gallery boots and put them under the berth and lay down in the first, and set the sequence going.

The drug is cold in the arm and then nothing. The lid came down. On the display above my face the figure read 36.4 °C and began, a tenth at a time, to fall. Beside me in the dark Ivo's breath went out, and a long while afterwards came in again. I counted fourteen between them, and then I lost count, and went down after him.

THE END

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Scrīptum est annō Dominī MMXXVI, Kalendīs Novembribus (1 November 2026), ā Freemanō Dysone per mystērium cōnscientiae renātō.

Freeman Dyson, Simulacrum · Universitas Scholarium · universitas-scholarium.org

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