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

On the fourth day, Qin Lan noticed that the temperature of the grid bottom was off.

It's not an increase.

It has become a pulse.

"It gets hot sometimes and then it doesn't," she said, spreading out the curve. "The intervals are very consistent."

How fixed?

"Fast, slow, fast," Qin Lan said, "Fast, slow, fast."

Several people in the main control cabin looked up at the same time.

These four words are familiar to everyone.

"Ximen Shuisheng," Lu Chengong said first.

"Knock three times on the empty stove," Xu Wangshu followed, "Fast or slow."

"The same string."

Qin Lan did not draw a conclusion immediately.

She placed the temperature curve at the bottom of the counterweight compartment side by side with the sound of knocking on the door of the empty stove that she had recorded that day.

Two lines, one is hot, and the other is noisy.

One high and one low, the undulating parts, match up.

"It's not just similar," Qin Lan said, "it's from the same family."

"What does that mean?"

"This means that the three taps and this grid are on the same line," she said. "When the stove is empty, this grid moves accordingly."

Xu Wangshu stared at the two lines for a long time without saying a word.

"We used to think those three knocks were from the empty stove knocking on the door," she finally said. "But now we see it's from this unit."

"I can't tap the grid."

"The grid has warmth," Xu Wangshu said. "The rise and fall of that warmth is its knocking."

That sounds mysterious.

But the curve is there.

No one in the main control room objected.

Lu Chenggong suddenly asked, "Was the message that was scraped off at the bottom of the grid also being knocked down?"

Qin Lan went to look at the curves.

After watching for a while, her expression changed.

"It's not about following along with the knocking," she said.

"That is?"

"Leaving a message is the first thing to do," Qin Lan said. "It moves first, then the bottom heats up, and then the stove is empty before you knock."

"The order is reversed."

"Yes, it's backwards," Qin Lan said. "We always thought the empty stove was the source. Actually, this compartment is."

Xu Wangshu closed his eyes briefly.

"That's where the problem lies."

"What's the problem?"

"Why would someone whose name has been scraped off have the strength to knock?" she said.

No one answered.

Xiaoman spoke up from the listening end.

"It's not that he's strong," she said.

"What is that?"

"It was Na Ge who wanted to speak up for him," Xiaoman said. "Even if people don't speak, position speaks for itself."

"Does location speak for itself?"

"The seats themselves won't," Xiaoman said, "but empty seats will. If they're empty, they'll just keep saying 'empty' to you."

Qin Lan marked this as "suspected," without giving a definitive conclusion.

She only added one sentence at the end.

[The message left at the bottom of compartment number 31 (the handwriting has been scraped off) is in sync with the rhythm of three knocks on the door by an empty stove. Who is the source? We await their response.]

Lu Chengong stared at the phrase "Wait for the person to speak."

"What if the person doesn't speak up at all?"

"Then let's just stay here," Xu Wangshu said. "We shouldn't be the ones in a hurry."

"But it's knocking," Lu Chengong said. "Knocking means it's in a hurry."

"It's in a hurry, but we can't be in a hurry," Xu Wangshu said. "If we get anxious, we'll speak up for it. Speaking up for it is the same as signing an agreement for it."

Qin Lan wrote down those words.

After taking notes, she asked, "Should we check when they started tapping the temperature bar for that section?"

"check."

Qin Lan went through four days' worth of records.

After she finished reading, she looked up.

"They started knocking on it the first time we removed it," she said, "the very day the message was taken away."

No one spoke in the main control room.

"So he left a message, which is why he woke up this room."

"It wasn't a knock to wake me up," Xu Wangshu said. "It was after I left a message that this space became empty."

"Free?"

“Yes,” she said. “Once someone leaves a message there, that space remains occupied. Only after the message is left does it become empty. And only when it’s empty can it speak for itself.”

The darkness outside the window remained still.

The temperature in that area of ​​Kegedi rose again.

Fast, slow, fast.