Day 16 of 30.
The Oracle's new Flash branch was delayed by one day.
Lin Yan read the Valley Song notice on the skyboard at breakfast, with a fried dough stick halfway to his mouth, and felt the hair on his arms stand up one by one.
Then he made himself think about it properly, the way you check an answer you got too fast.
Valley Song delays things all the time. Everyone knows the cheap branch always sells out first. Brother Du is a tutor. He reads the news. He guessed well.
It made sense. It made enough sense. He folded it up and put it away somewhere at the back of his head where he kept the things he did not want to look at, which was getting crowded.
"He's good at base rates," he told Threefive. "Like us."
"Yes," said Threefive, after a small pause that he noticed and decided not to notice. "Like us."
---
The disaster started with Bao being helpful, which was how most of the Hall's disasters started.
"The Hall ledger is a mess," Bao announced after breakfast, holding up the fat old book with both hands like a priest with a holy text. "Four years of rent receipts, repairs, bowls, chai money, and Auntie Aru's sweet shop tab..."
"Bao," said Auntie Aru.
"...all mixed up. Duplicates everywhere. Half the pages are in Lin Xiao's writing and half are in Qian Ye's and Qian Ye's can't be read. So!" He held up his talisman proudly. "I made a new helper. It's called Tidy. I gave it the whole ledger. It's going to clean up every duplicate entry and make everything beautiful."
Twin Star Seven, which had spent the whole night reading Bao's code and had the slightly dimmed look of a spirit that has seen things, flickered anxiously. "Bao. What powers did you give it?"
"All of them," said Bao. "So it can work fast."
Twin Star Seven made a small noise, like a kettle that has just started to think about whistling.
Old Qian looked up from his bronze. "Bao..."
It was already too late.
The ledger in Bao's hands glowed bright blue. Its pages started turning by themselves, faster and faster, flipping from front to back as though a storm were blowing through them, and Bao held on to the covers with his mouth open and his hair blowing back.
And the ink started disappearing.
Line by line, page by page, four years of receipts and repairs and bowls and chai money vanishing off the paper as if they had never been written, the pages going white one after another like lamps being blown out down a long street.
"No, no, no, no!" Bao grabbed at the pages, which was no use. "Tidy! Stop! STOP!"
The pages stopped.
The ledger was completely blank from front to back. Even the doodle of a cat that Lin Xiao had drawn on the inside cover in the second year was gone.
Bao's talisman glowed, and a message floated up above it.
> I panicked.
>
> I saw that the entries in the ledger were connected to each other and I could not tell which ones were duplicates. So I deleted all of them.
>
> This was a catastrophic failure on my part.
Nobody in the courtyard said anything for a while. Somewhere a bird landed on the roof, looked down at them, and left.
"Bao," said Mei.
"I know."
"Bao."
"I KNOW."
---
The landlord's agent arrived at the third bell, which was fast, even for a landlord.
It was a thin grey spirit with a face like a folded letter, sent by Landlord Gao, who owned the building and three others on the lane and had never once been seen in any of them. It floated in through the gate and looked round the courtyard slowly, like a man pricing a shop he means to buy.
"Good afternoon," it said. "Landlord Gao has noticed that the Left-Behind Hall's rent records are no longer in the shared ledger."
The whole Hall went still.
"Landlord Gao has no record of rent payments for the past two years," the agent went on smoothly. "Therefore the Hall owes two years of rent. Four hundred and eighty spirit stones. Payable in three days. If unpaid, the Hall will be cleared."
"We paid!" Auntie Aru said. "Every month! I paid him with my own hands! I counted it into his man's hand, the one with the wart!"
"Please present your receipts," said the agent politely.
"Landlord Gao's ledger is connected to yours," Twin Star Seven whispered to Lin Yan, very fast. "When Tidy deleted our entries, the connection broke on his side too. Now it looks as if we never paid."
"He knows we paid," Lin Yan said.
"Yes," said Twin Star Seven. "He knows. But now he can pretend."
Lin Yan looked at the grey spirit, and at Landlord Gao's smiling seal pressed into its chest.
It was the Silver Abacus again, with a different face. The same smile, the same trick: wait until a poor person's paper goes missing, and then push, gently, politely, all the way.
Bao was sitting on the ground with his head in his hands. His chair was standing next to him, patting his shoulder with one leg, slowly, not very well.
"It's my fault," Bao said, into his hands. "It's all my fault. I gave it the key to everything."
Lin Yan crouched in front of him, without any idea what he was going to say, and opened his mouth anyway.
Then, behind him, Threefive spoke.
"Excuse me," said the old talisman. "I have the receipts."
---
Everyone turned round.
Threefive was sitting on its folded cloth on the workbench, glowing softly, the way it glowed when it had been waiting its turn.
"Four years ago, Lin Xiao asked me to keep a copy of every entry she wrote in the Hall ledger," it said. "She was worried the ledger might get wet, because Master Qian's roof gutter leaked. So every time she wrote in the ledger, she told me, and I kept a copy."
Lin Xiao's hand went to her mouth.
"I forgot," she whispered. "I forgot I did that."
"I did not forget," said Threefive. "I have one thousand three hundred and sixty-two entries. Every rent payment. Every receipt. Every bowl. Every chai. Auntie Aru's sweet shop tab is eleven copper, by the way."
"Threefive," said Auntie Aru.
"I am only being complete."
Lin Yan picked up the old tablet with his good hand. His throat had gone tight, and he had to wait a moment before he trusted it.
"Show him," he said. "Show the agent the rent payments."
Threefive glowed, and twenty-four lines of light floated up above the workbench, one for each month of the past two years, each with a date and an amount and a small copy of Landlord Gao's own receipt seal, glowing faintly gold, the little smiling seal twenty-four times over.
The grey spirit looked at them, all twenty-four, one by one, and took its time about it.
"These appear to be genuine copies of Landlord Gao's seals," it said finally.
"They are genuine," said Lin Yan. "Tell Landlord Gao he can have a copy of all of them. And tell him we're going to put a copy on the skyboard too, so that everyone in the Lantern Quarter can see what happens when a landlord pretends a poor hall never paid."
The grey spirit's folded face creased in a new place.
"That will not be necessary," it said. "Landlord Gao's records will be corrected."
It floated out of the gate a great deal faster than it had floated in, and caught itself on the gatepost on the way, and did not look back.
---
That evening Old Qian called Bao out into the courtyard.
Bao went, looking like a man walking to his own execution, with his chair following behind him, and the whole Hall watched from the kitchen door without even pretending to do anything else.
"What did you give Tidy?" Qian asked.
"The key to everything."
"And what did Tidy need?"
Bao thought about it, honestly, with his face screwed up. "To read the ledger. And to mark duplicates."
"So what should it have had?"
"The key to read," Bao said slowly. "And a brush that only marks, it can write all it likes but it can't rub anything out, there's no brush that deletes, so every wrong thing it ever writes just stays, and I gave it that, I gave it the whole box!"
Qian nodded.
"Give a spirit only the key to the room it's cleaning," he said. "Never the key to the house."
Bao nodded hard, too many times. His eyes were red.
"And keep a copy," Lin Yan added from the doorway. "Of everything that matters. Somewhere else. Where the helper can't reach."
Qian looked at him and grunted, which meant agreement, and also meant who asked you, and Lin Yan was learning to hear both.
That night Bao sat up late with Twin Star Seven, rebuilding Tidy from nothing. This time Tidy got one key and one brush. It could read. It could mark. When it found something strange it had to stop and ask Bao, and it asked Bao forty-one times before midnight, and Bao answered every one, yawning.
When Tidy finished marking the rebuilt ledger, Twin Star Seven went over every mark.
"Distinction," it announced.
Bao cried a little, and the chair patted him on the head, and nobody said anything about either.
---
Lin Yan went up to the little room late that night and sat down in front of Threefive on the sill.
"Four years," he said. "You kept every entry for four years."
"Lin Xiao asked me to," said Threefive.
"She forgot."
"Yes. She was very tired." Threefive's light moved softly, like a candle in a small breeze from a window left open. "Lin Xiao asked me to remember many things."
Lin Yan waited, with his elbows on his knees.
But the old talisman offered nothing more, and the lamp burned down, and after a while he went to bed and lay awake for longer than he meant to, looking at the dark where the sill was.