I'm doing engineering in the instance.

Chapter 29 - Xiao Wu

"When a surge impacts," Xie Chengzhou said, "does the threat entity's perception and response become interrupted?"

Xu Kai glanced at him. "What did you observe?"

"The humming sound in the P2 direction stopped during the first surge," Xie Chengzhou said. "It reappeared after the surge subsided. One set of data has low confidence. I need to verify it twice more."

Xu Kai didn't speak. He shifted his gaze from Xie Chengzhou, glanced in the direction of P2, and then looked back at Xie Chengzhou.

"If your assumption holds true," he said, "the surge is the moving window."

"Yes," Xie Chengzhou said, "if it's true."

He pronounced the two words very flatly, without emphasis or pause, and then focused his attention on the direction of the surging waves, waiting.

The surging wave lasted for six to seven seconds. He memorized the time of the last surging wave and counted backwards. When he reached the sixth second, he firmly planted his foot and felt the steel plate beneath his feet.

The vibration began to increase at the seventh second.

The waves crashed against the bottom of the platform, and the vibration amplitude of the entire steel structure jumped up in an instant. Xie Chengzhou focused his attention on the P2 direction, waiting for that low-frequency hum.

The buzzing stopped.

It didn't gradually weaken; rather, at the moment the vibration amplitude reached its maximum, the buzzing abruptly stopped, as if something had pressed the pause button at that instant.

Xie Chengzhou memorized this timeline: peak vibration, cessation of humming, synchronization.

The surge receded.

The humming sound reappeared, coming from the direction of P2, low-frequency, even, lasting for about three seconds, and then stopped naturally.

"The second time," Xie Chengzhou thought to himself, then added a note to his memo: "Surge Impact - Second Verification: The buzzing stopped, synchronized with the peak vibration. Confidence level: Medium. Third data required."

"In conclusion," Xu Kai said.

"Let's assume," Xie Chengzhou said, "that we're missing one more set of data."

Xu Kai glanced at him but didn't say anything.

Xie Chengzhou closed the memo and scanned the screen on the platform.

He is looking for Wu Ming.

---

Wu Ming stood by the guardrail on the eastern edge of the P1 platform, head down, writing something in his notebook. Xie Chengzhou walked over, his steps light, a conscious control of the force of his footsteps—he had been walking like this on the P1 platform for about twenty minutes. Walking lightly wasn't a habit, but an operating procedure he had established on this platform.

He walked over to Wu Ming and glanced at the notebook.

This page is different from the previous one. The previous page had numbers and diagrams, environmental data; this page has text, densely packed, with very small characters, written very quickly, with a few words stopped halfway through and then restarted from the side, as if the hand was not quite obeying its commands.

Xie Chengzhou glanced at the page, then turned his gaze to Wu Ming's hands.

My hands are shaking.

It wasn't the slight, almost imperceptible tremor; it was the kind of tremor where the knuckles of the fingers holding the pen turned white and the pen tip left slight trembling marks on the paper. It was a tremor that lasted the entire time, but he never stopped.

"This is your first time entering a dungeon," Xie Chengzhou said. This wasn't a question.

Wu Ming looked up at him and said, "Yes," then paused, "How did you figure that out?"

"Your hand," Xie Chengzhou said.

Wu Ming looked down at his hand, then gripped the pen a little tighter, as if trying to suppress the tremor, but he couldn't, and the color of his knuckles turned a little whiter.

He didn't speak.

Xie Chengzhou stood to the side, neither leaving nor saying anything more, but simply keeping his eyes on the notebook and waiting.

"I don't know what to do," Wu Ming said, his voice low, as if he were talking to himself, "but I know it's better to write it down than not to."

Xie Chengzhou went over the sentence in his mind.

It's better to write it down than not to.

He himself never used this statement to say this, but the logic behind this statement is the same as the logic behind his memos: information is valuable, even if you don't know what use it is now, writing it down is a way to combat uncertainty.

He mentally reviewed Wu Ming's state: his first time entering the instance, his hands were shaking, but he was walking, memorizing, controlling his steps, using the sound of knocking to estimate the thickness of the steel plate, recording the surging wave cycle, and marking the amount of subsidence in the middle section of the pier.

His hands were shaking, but not a single one of his records was wrong.

"Your surge cycle data," Xie Chengzhou said, "how many times did you record it?"

"Eight times," Wu Ming said, "six to seven seconds, an average of six point three seconds."

"Error," Xie Chengzhou said.

"The shortest time is 5.8 seconds, and the longest is 7.1 seconds," Wu Ming said. "But there was one outlier, and after removing it, the average time is 6.2 seconds."

Xie Chengzhou went through the number and then compared his estimate with Wu Ming's data in his mind—his own estimate was six to seven seconds, while Wu Ming's data was six point two seconds. The error was within a reasonable range, and Wu Ming's data was more accurate because he recorded it eight times and removed outliers.

"Have you done surveying work before?" Xie Chengzhou asked.

"Civil engineering, third year," Wu Ming said, "not yet graduated."

Xie Chengzhou mentally marked the information: "Wu Ming, third-year student, Civil Engineering. Data collection ability: Effective. On-site judgment: To be observed."

He memorized the note but didn't write it down in his memo, because he wasn't sure if Wu Ming would see what he was writing.

"What were you writing down just now?" Xie Chengzhou asked, glancing at the page of text.

"The behavior of a threatening entity," Wu Ming said, "I was listening in as you described its perception mechanisms, and then I added in what I saw." He turned a page in his notebook and handed it over, "These are my observations."

Xie Chengzhou took it and glanced at it.

This page reads: "Threatening Entity - Preliminary Observations. When stationary, it resembles rust visually, requiring close proximity to distinguish it. Distribution density: Sparser above the waterline, denser below the waterline and in shaded areas. Movement behavior: No active movement was observed, but within approximately two minutes of Xie Chengzhou walking onto the pier, two near the edge of the pier showed slight displacement—direction of displacement: towards the pier, approximately three to five centimeters."

Xie Chengzhou read the last line twice.

"You see them moving," he said.

“It was very slight,” Wu Ming said, “but I was watching it closely, so I noticed it.” He paused for a moment. “It was triggered by the vibration from your footsteps on the pier, wasn’t it?”

Xie Chengzhou went over the question in his mind, then answered, "Most likely."

He returned the notebook to Wu Ming and mentally integrated this new information into the assessment framework of the threat entity: vibration triggers a response, which manifests as a slight displacement toward the vibration source, with a displacement distance between three and five centimeters. This means that a perception threshold exists, but it is not high. Xie Chengzhou triggered a slight response after standing on the pier for about two minutes. If he were walking, the response would be stronger.

He incorporated that into the design and then focused his attention back on the direction of the surging waves.

He waited for the third surge.

---

While we were waiting, Xu Kai walked over.

He walked with equally light steps, which Xie Chengzhou noticed—Xu Kai automatically adjusted his walking style after first seeing the information about the threatening entity, without being told or reminded; he did it on his own. This was the reaction of an experienced person, not someone entering a dungeon for the first time.

"What are you looking at?" Xu Kai said.

"Wu Ming observed that the threatening entity shifted slightly when I walked onto the pier," Xie Chengzhou said. "It was moving towards the source of the vibration, about three to five centimeters away."

Xu Kai glanced at Wu Ming, then at the notebook. "You're staring at them," he said. "Why?"

"Because he's walking on the pier," Wu Ming said, glancing in Xie Chengzhou's direction. "I want to know if they'll move."

Xu Kai paused for a moment, then looked away from Wu Ming without saying anything more.

Xie Chengzhou noticed the silence but did not speak.

He turned his attention back to the soles of his feet and felt the vibration of the steel plate—the surge was coming soon. He could feel the amplitude of the vibration slowly increasing, as if something was accumulating in the distance and then pushing it towards him.

"Watch the P2 direction," he told Wu Ming. "When the surge comes, tell me if the buzzing changes."

Wu Ming nodded and turned his gaze toward P2.

The surge is coming.

As the waves crashed against the bottom of the platform, the vibration amplitude jumped up in an instant. Xie Chengzhou firmly planted his feet, and the frequency he felt from the soles of his feet was clearer than the previous two times—he had established a baseline perception of this vibration, and now he could accurately feel the arrival of each peak of the surge.

"It's stopped," Wu Ming said in a flat voice, as if he were reporting data. "The buzzing stopped right when the wave hit."

The surge receded.

"It happened again," Wu Ming said, "three seconds, then it stopped."

Xie Chengzhou opened the memo and added a line after the last item in the "Pending Verification" column:

"Surge Impact - Third Verification: The humming stopped, synchronized with the peak vibration. Three data points, all consistent, without exception. Confidence level: High."

He paused after the word "high," then added in parentheses: "(Whether wave gap walking triggers a response has not yet been field-tested. High confidence assumption, not a confirmed rule.)"

Then he closed the memo.

"That's the third time," Xu Kai said. He had been standing there the whole time, and Xie Chengzhou knew he was watching, but he didn't speak until Xie Chengzhou had finished collecting the data from the three times.

"Three times," Xie Chengzhou said.

"So," Xu Kai said, "it can move when hit by the surge."

"Maybe," Xie Chengzhou said, "I need to go up to the pier to verify."

“You just went up there,” Xu Kai said. “They responded.”

"That happened during a lull in the swells," Xie Chengzhou said, "not during the impact of the swells. I needed to walk onto the pier at the moment the swells hit to verify if they were responding."

Xu Kai glanced at him. "You plan to use yourself as an experiment," he said, not as a question.

"Yes," Xie Chengzhou said.

Xu Kai paused for a moment, then said, "The surge impact lasts for about one second. How many steps can you take in one second?"

Xie Chengzhou did some mental calculations: his stride was about 70 centimeters, he could take about two steps per second, and move about 1.4 meters. The pier was about 2 meters wide, so if he stepped onto the pier from the P1 platform, he could reach the middle of the pier in one second.

"Two steps," he said, "about 1.4 meters."

“Not enough,” Xu Kai said. “It’s 30 meters from the pier to P2. At two steps per second, it would take 21 waves, about 130 seconds.” He paused for a moment. “But you don’t need to walk the whole way in one go. You can stop between waves and wait for the next wave before you walk again.”

Xie Chengzhou went through the calculations and then compared them with Wu Ming's data in his mind: the surge cycle was 6.2 seconds, each impact lasted about one second, and the interval was about five seconds—he had to stop moving within five seconds, otherwise the vibration would trigger the sensory response of the threatening entity.

This means that each surge has only a one-second window to move, and each interval has a five-second requirement to remain still.

He mentally went through the rhythm, then focused his gaze on the pier.

The slight subsidence in the middle of the pier means that the supporting nodes are not strong enough, and the vibration will be greater when hit by surging waves. If he steps on that node, the vibration will be transmitted directly from his feet. He needs to judge the footing position within a second and avoid that node.

This is not a simple question.

"What are you thinking about?" Wu Ming asked.

Xie Chengzhou looked away from the pier and glanced at him. "I was thinking about that sinking point in the middle of the pier," he said. "The vibration at that point will be greater when the waves hit, so we need to avoid it."

Wu Ming glanced down at his notebook. "The sinking location is in the middle of the pier, slightly to the east," he said. "Approximately between the fourth and fifth nodes, about twelve to thirteen meters from the entrance to the P1 platform."

Xie Chengzhou memorized this number.

It would take about nine waves to reach that location, which is twelve to thirteen meters, based on two steps per second. Before those nine waves, he needs to complete the first verification at the entrance of the P1 platform—stepping onto the pier, standing firm at the moment of the wave's impact, and observing whether the threat entity responds.

If the response indicates the assumption is false, he returns to the previous state.

If there is no response, the assumption holds true, and he continues.

He mentally went through the process, then opened his memo and wrote a line on the last page:

"#003·Verification Plan·Surge Window Field Test: P1 → Pier Entrance, step into the surge the instant it hits, and observe the threat entity's response. Success condition: No response. Failure condition: Response or ergonomic failure. Execution time: Next surge."

He read the line once, then closed the memo.

"You don't plan to tell anyone else," Xu Kai said.

"Tell them what," Xie Chengzhou said.

"Your assumption," Xu Kai said, "is that if the surge is a moving window, they need to know it."

"I'll say something after I confirm it," Xie Chengzhou said. "Assumptions aren't information; only verified assumptions are."

Xu Kai glanced at him. "You think differently from me," he said. "I'll state the assumptions first, let everyone know the direction, and then verify them."

"Your approach creates expectations," Hsieh Cheng-chou said. "Expectations become a burden when you assume failure."

Xu Kai paused for a moment, then did not refute.

Xie Chengzhou shifted his gaze from Xu Kai and glanced at Wu Ming.

Wu Ming wrote a few more lines in the notebook, his hand still trembling, but his handwriting was a little steadyer than before.

Xie Chengzhou memorized this detail but didn't say it aloud.

He turned his gaze to the entrance of the pier and felt the steel plate beneath his feet—the next surge was about five seconds away.

He planted his foot firmly and waited.