1Nell Brandt was eighty-seven. She lived alone in the house in the iron hills and would not be moved from it. Her husband had been dead twenty years. The small brass lamp burned by her bed, as it had for fifty-six years, and she had changed the bulb in it more times than she could count.
2Lucy was sixty. She had left the house of the far travellers and come east, to a town on the cold bay near the city of schools on the river, to be near her daughter Ruth and Ruth's girl, Nora. Every second week she drove five hours south to the iron hills. She filled her mother's shelves, and was told that she fussed.
3Nora was seventeen, and good at sums. It ran in the women of that house like red hair. She built small learning machines on her own screen, late at night, and she was restless. She had reached the age when a clever child finds she can do whatever she is set, and does not know what to set herself.
4"They keep telling me to choose a road," she said to her grandmother. "Every road they show me, I can see the end of it from here. And the end is a room."
5"I knew a mine like that," said Lucy.
6In the eleventh month of that year Nora asked her grandmother to come with her to a hall. It was in the next town, at a school, where there was to be a day of short talks. Each speaker had a few minutes to say the one thing they knew. A man was going to speak on what a mind is.
7"He says he has it in one line, Gran. One line of numbers."
8"Then he is a fool or a wonder," said Lucy, who did not like a loose answer any more than her mother did. But she went.
9It was a plain hall, with some hundreds of people on hard seats. The speaker was Alex Wissner-Gross, a young man, a scholar of physics and of reckoning machines, who had been trained at both of the great schools on that river. In the spring of the year he and a maker of proofs named Cameron Freer had printed a short paper, in the journal where the physicists publish their letters to one another. He had come to say in plain words what was in it.
10He began with a question, and he did not hide how large it was. "Is there a single equation for intelligence?"
11Lucy folded her arms.
12Then he put the line on the wall. She had read ten thousand lines of signs in her working life, and she read this one as easily as the name of a street. A force. A strength. And the slope of a count: the count of all the different futures that can still be reached, out to a certain distance ahead in time.
13She knew that count. It was the old measure of the men of heat, the number of ways a thing can be. It was the measure that the quiet man on the wheel had found again in his messages, and had called by the same name, and had never said why one shape should serve both. Her mother had told her that at the kitchen table.
14And here it was a third time, turned to face forward. It did not count the ways a thing is. It counted the ways a thing may yet go. And the line said there is a push toward wherever those are most.
15"In short, intelligence doesn't like to get trapped," the man said.
16Something moved in Lucy's chest that had not moved for a long time.
17Then he showed pictures. He and his fellow had made an engine that did one thing only. Whatever small world it was set down in, it leaned always toward the place from which the most futures could still be reached. They had given it no task. There was no cheese in its house, and no bell.
18On the wall was a cart on a line. On the cart was a pole, hinged at its foot, free to fall to either side. A pole lying flat can do one thing more, which is to lie there. A pole standing can still go anywhere. The cart ran a little to the left. It ran a little to the right. The pole swung up, and stood, and trembled. And the cart went on running under it, this way and that, catching each fall before it was a fall.
19Lucy made a sound. Nora looked round at her.
20She was seeing a long hall in the hills of New Jersey, which she had never seen, and a thin grave man coming down it on one wheel with no handles. He leaned a little forward and the wheel ran to catch him. He stayed up only by always being about to fall, and always mending it. Her mother had thought about that for years, and had not known what she was thinking about.
21There was more. There was a large disc and a small disc, and a third disc held fast in a narrow place where the large one could not go. Nobody had told the large disc to do anything. It took up the small one, and pushed it into the narrow place, and knocked the third disc free. A world with the third disc loose in it had more roads than a world without. It was a beast with a stick. Then there were two discs that pulled the two ends of a cord at the same moment, for neither alone could open what was shut.
22Nothing, the man said, had told the engine to do any of this.
23And Lucy Brandt, sixty years old, on a hard seat in a school hall, was nine years old with her palm on wet stone. I didn't want any one place. I only wanted to not be shut in. I wanted there to be more ways, and not fewer. Who put that in me? Her mother had said: nobody knows that yet. Ask it again when you're grown.
24She had not asked it again. She had forgotten that it was a question. She had thought it was only what fear feels like.
25Now be careful here, as she was careful, for she was Nell's daughter. The man did not say the thing was proved, and it was not. It was put forward. It had been shown in small worlds drawn on a screen: a cart, a pole, a few discs. Other scholars asked hard things of it afterward. How far ahead should the count run, and who chooses that? Can so short a line carry so great a weight? Those are fair questions, and they are not all answered as I write. The line may be mended. It may be bettered, or set aside for a truer one. That is no weakness in it. The Fire has never worked in any other way.
26But it had been written, in the same kind of signs that tell how a stone falls. Anyone might now pick it up and test it.
27They were crossing the yard to the car, in the dusk, when Lucy's telephone rang. It was Mrs. Dombrowski, who lived on the next lot to Nell's and looked in on her each day. Nell had fallen in the kitchen that morning. Nothing was broken. But the doctor had come, and listened to her chest a long time, and said her heart was giving out. He wanted her in the hospital. Nell had told him no. She had got into her own bed, and asked for the lamp to be moved to where she could see it.
28"He says days," said Mrs. Dombrowski. "But I have sat with a few, and I'd say less. I would come now."
29It was five hours' drive, and sleet was beginning to fall. Ruth was away in another city. Nora said, "I'm coming," and was in the car before Lucy could answer.
30They drove south and west through the dark. The sleet turned to freezing rain. Signs above the road warned of ice. Lucy drove faster than she should have. She knew it, and for an hour she did it anyway. She had a thing to tell her mother. For the first time in many years she was afraid of a drawer closing.
31On a long bridge over a wide river the car let go of the road.
32There was no sound. The wheel went light in her hands. The rail of the bridge began to swing slowly across the glass in front of them, from the right side toward the middle. Nora said, "Gran," in a very small voice.
33Everything in Lucy's body wanted to do something large. It wanted to stamp on the brake and haul the wheel over. But she had sat for thirty years in a room of people who steered things they could not touch, and she knew what a large act does to a thing that is already sliding. It spends in one throw every mending you had left.
34She took her foot off. She turned the wheel a little toward the slide. The car hung. She turned a little back. It hung. The rail went past the glass the other way, more slowly. Then the tyres found something, and the road was under them again.
35She drove the rest of the bridge at the pace of a walking horse. At the far end she pulled off and sat with her hands shaking in her lap.
36"You hardly did anything," said Nora.
37"No." Lucy got her breath. "That's how you keep a next thing to do." She looked at the ice shining on the road ahead. "We'll go slower. If we come too late, we come too late. That is better than not coming."
38They went slower. It cost them an hour and a half.
39They came up the hill road at half past three in the morning. A light was burning in the kitchen, and Mrs. Dombrowski was asleep in a chair. From the room at the back, through the open door, came an orange glow no bigger than a thumb.
40Nell was awake. She was very small in the bed, and her breath was short. But her eyes were as they had always been.
41"You drove in this," she said. "Fool. And brought the child."
42"I had to tell you a thing, Mama."
43"It could have waited."
44"No," said Lucy. "It couldn't."
45She sat down on the bed. Nora sat on the floor against her knees, where Lucy herself had sat once, on another night. And Lucy told it. She told of the hall, and the line on the wall. She told of the count of the ways not yet taken, and the push toward where they are most. She told of the engine with no cheese, and the disc that used a stick.
46"And there was a pole, Mama. On a cart. Nobody told it to stand. It stood because, standing, it could still go anywhere. And the cart kept running to catch it."
47Nell's eyes went to the ceiling. "Down the hall," she said. "Past all our machines. With three balls going." Her hand moved on the blanket. "We thought he was playing."
48"You told me to ask again when I was grown. At the aunt's house, with the candle. I asked who put it in me, to want more ways."
49"I remember. I had no answer. I hated that."
50"There is a man who says nobody put it in. He says it may be what a mind is. Before any cheese."
51Nell lay still. Then she asked what Lucy had known she would ask. "Is it proved?"
52"No. It is proposed. Two men, one paper, some discs on a screen. People are arguing."
53"Good," said Nell. "I never trusted a thing that came in finished." She waited for her breath. "Someone will have to check his sums."
54"Yes."
55Her eyes came down to the girl on the floor. "Are you any good at sums?"
56"Yes," said Nora. It was not a night for modesty.
57"Then check them. Do not believe him because your grandmother cried in a hall. Do the work." She turned her head on the pillow, toward the lamp. "Unscrew that when I have finished with it. It goes to her. My father took it off a wall by the sea. He said it only ever meant one thing." She shut her eyes. "It is a small thing to hand on. But I notice it is still lit."
58She slept soon after. She did not wake again in any way that could be spoken to. Near noon of the second day she went through the Last Door, in her own bed. The freezing rain was long over, and the sun was on the hills.
59Lucy unscrewed the lamp that evening. The brass was still warm. She put it into Nora's two hands and closed the fingers over it.
60Nora took it home and wired it up by her desk. It burns there beside the screen where she builds her learning machines, and beside the paper of the two men, which she has by now been through many times with a pencil. She has found two places where she is not satisfied. No one has told her what to want.
61Now hear the last of this book. The line was written, and printed, and spoken in a hall, and the world did not stop for it. Most people never heard of it. In that same season the learning machines were growing by the month. Each ran harder to its bell, and those who set the bells were in a hurry. Whether the thing now being built will close ways or keep them is not settled. It is being settled now, in rooms you could walk into.
62So the ember has come all the long road down. It was a coal under a rock ledge. It was carried in a clay pot. It was a temple lamp, a candle, a furnace, a glowing valve above a wire-man's set. It was a point of blue in a bar of light, and a black box with a label on it. Now it is in the glow of whatever you are reading this by.
63There is no keeper further along the road than you. The lamp is lit. Someone is listening.