Forty Arms

The first person to come was Garrow.

Teo would never have guessed it. Not in a hundred years. The pyre-man who had spoken twelve words to him in two years — who had told him to pray harder — who had stood in Tallow Row with a torch in his fist while the crowd dragged Maud out of her hut... walked into the Mercy House on the first morning after Mira wrote the word sixteen in her grey book, and stood in front of Teo, and held out his arm.

He did not say anything. He did not need to.

Teo looked at him for a long moment.

"...Why?" he said at last.

Garrow looked down at him. His face, lime-burned and weathered, was as unreadable as ever.

"I carry them," he said. "Every day. Since the Harvest. Children." He paused. "You carry them too. You know."

That was all. But it was more words than Garrow had ever said to him in one breath, and Teo heard everything that was underneath them.

Mira made the scratches. Garrow did not even flinch.

The next morning, there were three more. Cobb, the young acolyte who had kept the Mercy House running alone for a month... he asked for it shyly, as if he were asking for a second bowl of soup. Then a woman from Tallow Row whose husband had died in the first week. Then her eldest son.

The morning after that, there were eleven.

Word moved through the Sump the way water moved through the cracks in the Spillway... slowly, silently, everywhere at once. Teo never knew exactly who told whom, or what they said. But he could guess. The cart-man who took the handle off Saint Orlen's pump. The acolyte who spoke at the burning. They went east, past the Ashlands, and they came back with something. A cow-scratch. From the Fens. The milkmaids never get the pox, everyone knows that. The cart-man put it in his own arm, and then he put the red pox in it, and he lived. Nothing happened. Nothing at all.

And underneath it, unspoken: The Chantry has gone up to the Crown and shut the gates. The cart-man came down into the Sump and opened his arm.

By the end of the first week, there were forty.

That was when Teo realised they had a problem.

Bram's clay pot of threads was nearly empty. He had brought a great many, but each person needed one, and there were three thousand people left in the Sump, and the Fens were three days away down a half-frozen river. Bram could go back. He would go back... he had already said so, in his slow, flat way, as if it were not a question. But it would take a week, there and back, and the threads might spoil on the way, and even then, there would not be enough.

The answer was in the red book. It always was.

Jenner had faced the same problem, a hundred years before the Makers flew. He had had a single dairymaid, Sarah Nelmes, and a single blister on her hand, and a whole country to protect. So he had done something very simple. When the cowpox blister rose on James Phipps's arm, eight or nine days after the scratch, Jenner had opened it, and dipped a fresh thread in the fluid, and used it to scratch the next child. And when that child's blister rose, he used it for the next. And so on, arm to arm, from one person to the next, like passing a flame from candle to candle.

The cow-blister did not need a cow, once it had a person.

So on the ninth day after Garrow's scratch, when a pale blister the size of a fingernail had risen on the pyre-man's arm with a dimple in its centre, exactly like Teo's, Mira opened it with a clean knife and drew a dozen fresh threads through it. And that afternoon, a dozen more people walked out of the Mercy House with scratches on their arms.

And nine days after that, each of those twelve had a blister. Which made a hundred and forty threads.

Teo sat up late that night with Mira's grey book, working it out.

Each blister could make a dozen threads. Perhaps more, if they were careful. And each new blister rose about nine days after the scratch. So every nine days, the number of people they could protect was multiplied by twelve. Forty, then nearly five hundred, then...

He stopped, and stared at the number, and did the sum again, slowly, because he did not believe it.

Six thousand. In less than a month.

More than the whole Sump.

'It's like the flux,' he thought, with a strange chill. 'But backward. The flux spread from one person to another, and so did the red pox. Every sick person made more sick people. And this spreads the same way. Every protected person makes more protected people.' He looked at the scab on his own arm. 'The red pox doubles. We multiply by twelve.'

'...For once, the arithmetic is on our side.'

Mira kept the count.

She was very strict about it. Stricter than Teo had ever been, even in the cellar with the map of the flux. Every person who was scratched had a line in the grey book. Their name. Their street. Their age. The day of their scratch. The day their blister rose, or if it did not rise at all. And then, every day after that, whether they were well, or whether they had the red pox.

And beside them, she kept another list. The ones who had not been scratched. Their neighbours. Their families, sometimes, who had refused, or been too frightened, or too far gone in grief to care. Same streets. Same houses. Same air.

"Because otherwise," she said, when Nell asked her why, "we won't know anything. If a hundred people with scratches don't get the pox, that's wonderful. But it doesn't mean anything unless we know how many people without scratches did get it. In the same streets. At the same time." She tapped the grey book. "It's like the bread. We had to count the ones who ate Fell's rye and the ones who didn't. Otherwise it's just a story."

Nell considered this.

"So you need people to get sick," she said slowly. "To prove it works."

Mira was silent for a long moment.

"No," she said at last, very quietly. "I need to know when they do. That isn't the same thing. I'll never stop anyone from being scratched to have someone to count. But some people won't come. They're frightened, or they think it's heresy, or they think it's too late. And some of them will get the pox. And when they do..." She looked down at the book. "I'll write it down. Because then their dying will teach us something. And that's better than it teaching us nothing."

Nell looked at her for a long time. Then she went and sat on the stairs and did not say anything else for the rest of the evening.

The next morning, she came down to the Mercy House with Teo, and stood in front of Mira, and pushed up her sleeve, and held out her thin arm without a word.

Teo watched Mira make the scratches. His hands were clenched so tightly that his nails cut into his palms.

At the end of the fourth week, Mira closed the grey book, and handed it to him without a word, and went and sat outside on the steps of the Mercy House in the cold, alone.

Teo read it. Slowly. Twice.

Two thousand one hundred and six people had been scratched. Of those, one thousand nine hundred and eighty had grown a cow-blister on their arm, the way they were supposed to. The rest had not — perhaps the thread had been weak, or the scratch too shallow — and Mira had scratched them again.

Of the people with a cow-blister, eleven had caught the red pox afterward.

Eleven. All of them in the first few days after their scratch... before the blister had risen, before the body's defenders had finished learning. Teo had read about that in the red book. The pox had already been inside them, quietly growing, before they ever came to the Mercy House. The cow-blister had been too late. Three of them had died. The other eight had been ill, and lived, and Mira had written beside each of their names: mild.

And in the other list...

In the same streets, the same houses, over the same four weeks, among the people who had not come — nine hundred and forty of them — the red pox had taken two hundred and twelve.

Teo sat in the hall of the Mercy House with the grey book in his lap, and looked at the numbers for a very long time.

Then he went outside and sat down on the cold step beside Mira.

She was not crying. Her face was very still. She was looking out across the Sump, at the frozen alleys and the tenements and the pale smoke of the pyres, which were fewer now. Much fewer. Perhaps three, tonight, where there had been a dozen.

"Eleven," she said quietly. "And two hundred and twelve."

"Yes."

"One in two hundred," she said. "Against one in four."

Teo did not answer. He did not need to. She had done the arithmetic herself. She always did.

They sat there for a long time on the step, in the cold, side by side.

And then, from the dark street below them, someone called up, quite cheerfully:

"Is this where they're doing the cow-scratch? My mam says I've to have it."

Teo looked down. It was a boy of about twelve, with a runny nose and a ragged coat, standing at the bottom of the steps with his hands in his pockets.

Mira wiped her face with the back of her hand, and stood up, and smiled.

"Yes," she said. "Come in."