Don't go to the moon, there are gods on the far side of the moon.

Qin Lan did the math.

"The list of external witnesses is from ten years ago," she said. "There are forty-seven slots available."

"What's wrong?"

"Most of those people from ten years ago are now in their forties or fifties." She spread out the booklet. "Number 31 was added to the list ten years ago."

"What does that mean?"

"That means if Number 31 were alive now," Qin Lan said, "he would be in his forties or fifties."

"If I were alive."

"Yes," she said, "I meant 'if'."

There was a moment of silence in the main control room.

"Three years ago, Lu Chenggong was registered for this position," Xu Wangshu said. "At that moment three years ago, no one had ever seen number 31 in person."

No one has ever seen it.

"How long has this seat been vacant?"

"Ten years," Lu Chenggong said, "or longer."

Qin Lan wrote down the words "ten years" and then added a question mark next to them.

"A position has been vacant for ten years," she said. "Why the sudden need to fill it now?"

"Because the fragments started to heat up."

"Yes," Qin Lan said, "because someone is going to set a fire here."

Xu Wangshu stared at the booklet.

"So the question isn't who number thirty-one is," she said.

"What is that?"

"Who will need this name to be filled in ten years from now?"

When this question was raised, no one in the main control room answered it immediately.

After a long pause, Lu Chengong said, "Should we issue a notice and look for them?"

"Who should I look for?"

"Find number 31 himself."

Xu Wangshu shook his head.

"no."

Why?

"Because we don't know his name," she said. "Once an announcement is made, we have to name him. Once we name him, it's like we've filled in that blank."

"Then we just stay put?"

"We'll move," Xu Wangshu said. "We'll set up a location."

"Set the location?"

"Leave compartment number 31 standing there, untouched," she said. "Don't lock the door, don't seal the compartment, and keep the number. Whoever comes can speak."

"That's called waiting for a rabbit to run into a tree stump."

"No," Xu Wangshu said, "Then it's called—we'll set out the chairs and wait for him to sit down."

Lu Chengong thought for a while and then nodded.

"What if he doesn't come?"

"That stool is empty."

"If it's empty, what about the Zhurong Terrace?"

"We want someone to fill the position at Zhurong Terrace," Xu Wangshu said. "Our meaning is: this position can only be occupied by the owner himself."

Qin Lan wrote this down.

After she finished writing, she gave me a reminder.

"But—" she paused, "what if Number Thirty-One himself died ten years ago?"

The main control room fell silent.

Xu Wangshu did not evade the question.

"But those spaces have to be left empty," she said. "Dead people can't fill them, but living people can't occupy them either."

Why?

"Because we had already taken the place, we signed the document on behalf of a dead person."

After she finished speaking, she looked out at the darkness.

"The human realm can accept one cell remaining empty indefinitely."

"But it's unacceptable that one of the spaces was filled in by us without thinking."

After copying the sentence, Qin Lan looked up and asked, "Should we send out the origin of this section?"

"No," Xu Wangshu said.

"Why not post it? If you post it, the person in question might see it themselves."

"Because the origin of number 31 is itself a name," Xu Wangshu said. "Once we write it down into something that can be circulated, it's like posting a lost and found notice on it."

"What's wrong with a lost and found notice?"

"A lost and found notice is for things to be claimed," she said. "But number 31 isn't something; it's a person. People don't need to be posted; they'll come back on their own."

After listening for a while, Lu Chenggong suddenly asked a question.

"What if the person who comes back," he said, "is not Number Thirty-One himself?"

There was a moment of silence in the main control room.

"Then we definitely shouldn't put up notices," Xu Wangshu said. "If we do, the first person to come will just pick it up."

What would happen if they picked it up?

"The person who picks it up will use it as their name," Xu Wangshu said. "In that case, we're not just filling in a name for someone else; we're giving away a name for free."

She picked up her pen and wrote this down as well.

[Slot number 31 is listed for the person who claims it; it will not be posted, shared, or claimed on behalf of others. The person must identify themselves; claiming a slot based solely on its location is not permitted.]

After she finished writing, she put down her pen.

"All we can do is keep this spot lit."