I'm doing engineering in the instance.

The surge is coming.

Xie Chengzhou planted his foot firmly and felt the peak of vibration from the bottom of the steel plate travel up from his feet—not gradually, but suddenly, as if something had accumulated enough power in the distance and then pushed it all at once, pulling the vibration frequency of the entire platform to its highest point within a second.

He stepped onto the pier.

First, he stepped firmly onto the steel plate and felt the vibration amplitude—it was greater than that of the P1 platform, but within expectations. He had marked this difference in the evaluation framework beforehand, and now the numbers matched. Second, he avoided the sinking node in the middle section to the east, and stepped about 30 centimeters to the left of the node. The vibration was transmitted from the sole of his foot and was uniform, without any abnormal peaks.

He stopped.

The surge was still crashing. The peak of the tremors hadn't passed yet. He stood on the pier, focusing his attention on his surroundings—

The steel maggots didn't move.

The few birds near the edge of the pier remained in place, clinging to the side of the steel structure, their phosphorescence flickering slightly. They did not move toward the source of vibration, did not gather, and did not respond in any way.

The surge receded.

At the same moment the surge receded, Xie Chengzhou retreated back to the P1 platform. His steps were light and quick, covering the distance he had taken to enter in three steps. He retreated to the edge of the platform, stood still, and felt the vibration under his feet—normal, during the break in the surge, the steel plate vibration returned to the baseline level.

He opened the memo.

"#003·Surf Window Field Verification·First Time: Stepping into the pier entrance, during the continuous surge impact, the threatening entity did not respond. Hypothesis valid. Confidence: High."

He paused after the word "high," then added a line: "Note: Single verification, multiple confirmations required. Current conclusion: Vibration saturation during surge impact may cause the sensing threshold to fail."

He closed the memo.

Then he heard Xu Kai's voice.

---

"You can leave when the surge comes," Xu Kai said, standing in the center of the P1 platform. His voice wasn't loud, but the platform wasn't large, so everyone could hear him. "During the peak of the vibration, the perception of the threatening entity becomes ineffective. This is the result of what we just verified."

Xie Chengzhou shifted his attention away from the memo.

Everyone else was looking at Xu Kai, and their expressions were all different—Old Chen was nodding, Liu Feng was frowning, Lin Xiao was looking towards the pier, and Wang Bo was rubbing his hands together as if he was preparing something.

"Wait a minute," Xie Chengzhou said.

He didn't raise his voice, but Xu Kai stopped and turned his gaze to him.

"This is a verification," Xie Chengzhou said, "not a confirmation of the rules."

"The results are consistent," Xu Kai said. "Three observations, one field study, and the data from all four studies are consistent."

"A field verification," Xie Chengzhou said, "is needed. At the entrance to the swell, it's about 1.4 meters, just two steps away. The pier is 30 meters long, with a sinking node in the middle, where the vibration transmission characteristics are different from the entrance. I need to conduct a verification in the middle and another at the sinking node before I can say that this route is feasible."

Xu Kai glanced at him and said, "How many verifications do you need?"

"Sufficient number of times," Xie Chengzhou said, "before I have enough data, it's an assumption, not information."

"They need direction," Xu Kai said, "not to wait."

"They need accurate information," Xie Chengzhou said, "not to risk their lives to verify your assumptions."

The platform fell silent for a moment.

Lin Xiao turned her gaze away from the pier. Old Chen placed his hands on his thighs and remained silent. Wu Ming put down his pen in his notebook.

Wang Bo stood up.

"I'll try," he said. "I want to know too."

Xie Chengzhou turned his gaze to him. "No," he said, "wait until I finish the mid-stage verification."

"You only took two steps before coming out," Wang Bo said. "You yourself said the middle section is different, so how do you know the verification result for the middle section?" He paused for a moment. "I'll go first. If everything's fine, you can go on."

"Wang Bo," Xie Chengzhou said.

But Wang Bo had already reached the entrance of the pier.

He stood there, waiting for the surge.

Xie Chengzhou mentally calculated the time: about three seconds since the last surge, and according to Wu Ming's data, the next surge would be in three seconds. He glanced at Wang Bo's stance—his center of gravity was high, and his heels were slightly raised, like a starting position for running. It wasn't the construction site stance; it was his own habitual stance, which was unstable.

"Lower your center of gravity," Xie Chengzhou said. "Put your heels firmly on the ground and don't use your toes to exert force."

Wang Bo stepped down with his heel, but not completely, and Xie Chengzhou could see that his calf muscles were tense.

The surge is coming.

Wang Bo stepped onto the pier.

The first step was correct; his foot landed firmly at the entrance. The vibration traveled up from the soles of his feet. He paused, regained his footing, and the steel maggots didn't move. He glanced back, and Xie Chengzhou saw something relax on his face—that expression of briefly believing he was safe in the face of danger, the most dangerous expression.

He took the second step.

The surge receded.

It wasn't sudden, but gradual. The peak vibration began to drop, and as it moved downwards from its highest point, Xie Chengzhou felt the frequency under his feet decreasing—the gap in the surge had begun, the vibration was subsiding, and the perception threshold was recovering.

Wang Bo is still walking.

"Stop," Xie Chengzhou said, his voice low but firm, "Stop moving."

Wang Bo heard it and stopped—but he stopped by dropping his foot from the air, landing on the third step. The moment he landed, the vibration traveled from the sole of his foot to the steel plate, from the steel plate to the trestle structure, and from the trestle structure to the steel maggot's range of perception.

Intervals between swells.

The vibration threshold has been restored.

The steel maggots near the middle of the pier started to move.

It wasn't a slight displacement, but a rapid movement—they detached from their attachment points and converged along the surface of the steel structure towards the trestle bridge. Their speed was faster than Xie Chengzhou had estimated, about 1.5 times the walking speed. Their mineralized shells emitted a low, grating sound as they moved, like metal scraping against metal, but duller and wetter.

Wang Bo heard that voice.

He glanced back, then he started running.

Xie Chengzhou was already walking towards the entrance of the pier. "Don't run," he said, "Don't run, vibration—"

Wang Bo was running, his footsteps echoing across the steel plate. Each step was a peak of vibration, more localized and concentrated than a surging wave, traveling directly from the soles of his feet to the steel plate he stood on, and to the steel maggots beneath his feet.

He ran three steps.

When he landed on his third step, the steel plate beneath his feet made a sound.

It wasn't a cracking sound, but the kind of sound metal makes when it corrodes to a critical point—a low, short sound, like something collapsing inside, followed by the outer shell. Xie Chengzhou recognized the sound; he'd heard it on construction sites. It was a precursor to fatigue failure in steel structures, and there was usually a 0.3 to 0.5 second window after that sound appeared.

He stopped; he didn't go any further.

He knew he couldn't make it through.

The steel plate beneath Wang Bo's feet bent, not the whole piece, but a part of it—the area corroded to the brink by the steel maggots. With the combined effect of his weight and the vibrations from running, the corroded edge began to expand, and the steel plate bent downwards. Wang Bo felt it and took a step to the side, but there were already two steel maggots attached to the steel plate next to him. The moment his foot stepped down, he stepped on one of them.

The steel maggot's shell wasn't broken, but it reacted very quickly—Xie Chengzhou later wrote in his memo, "Respond to contact immediately, without delay"—it started secreting corrosive liquid from the moment it was stepped on, and Wang Bo's shoe sole began to dissolve within half a second. He felt it, and he made a sound, not a shout, but the kind of sound that comes out of the throat before consciousness reacts, short and abrupt.

He jumped to the side, but the bent steel plate had already broken the moment he jumped.

The sound of breaking was very short.

Then came the sound of falling. It wasn't a long one. The platform was about five meters above the water. Wang Bo didn't scream during the fall. There was only the metallic sound of steel plates breaking and the sound of water impact. The sound of water impact was almost inaudible in the background noise of the surging waves, but Xie Chengzhou heard it.

He stood at the edge of the P1 platform and glanced down.

The water level has been restored.

nobody.

---

No one spoke on the platform.

Lin Xiao covered her mouth with her hand; her shoulders were trembling, not from crying, but from the kind of trembling one experiences in extreme fear trying to control oneself—Xie Chengzhou recognized this. Old Chen lowered his head, placing his hands on his knees; the veins on the back of his hands were clearly visible. Dr. Cao stood up, walked to the edge of the platform, glanced down, then stepped back, his face pale.

Wu Ming didn't move. He remained seated in his original spot, his notebook still in his hand, but he wasn't writing anything. He was staring at the broken gap at the entrance of the pier.

Liu Feng stood there, his expression unchanged, but Xie Chengzhou noticed that he clenched his hands tightly for a moment, and then relaxed them.

Xu Kai was next to Xie Chengzhou, and he was also looking at the gap.

"Your hypothesis," Xie Chengzhou said in a flat voice, "is now supported by verification data."

Xu Kai did not answer immediately.

"His judgment was wrong," Xu Kai said. "He knew the rule that the gap between the swells could not be moved."

"He knows the rules," Xie Chengzhou said, "but he doesn't know the boundaries of the rules. He doesn't know the speed at which the surge recedes, he doesn't know the combined effect of the vibrations of his footsteps and the surge, he doesn't know the extent of corrosion on that steel plate—he doesn't know these things because you told him he could walk when the surge came, and he thought he knew."

Xu Kai glanced at him.

"What do you want to say?" he said.

"What I want to say is," Xie Chengzhou said, "next time you have a hypothesis, tell me first, and then tell them after I've verified it."

Xu Kai paused for a moment, then said, "You have no right to decide how information flows."

"You have no right to use other people's lives to verify your hypothesis," Xie Chengzhou said.

The platform fell silent again.

The surge came and then receded, as if nothing had happened.

Xie Chengzhou shifted his gaze from Xu Kai to the gap at the entrance of the pier—the broken steel plate was gone, leaving only the corrosion marks on the edges and the gap between the two steel plates, about forty centimeters wide.

He mentally replanned the route.

The gap can be crossed, but it must be done during the impact of the surge. At the peak of the vibration, cross the 40-centimeter gap. The landing point needs to be precisely controlled. There is a corrosion mark about 30 centimeters to the right of the landing point, which should not be stepped on.

He wrote these down in a memo and then closed it.

"I continued to verify," he said, "the middle section, then the sinking node. No one stepped onto the pier until I was finished."

No one objected.

Xie Chengzhou waited for two surges.

The first time, he stepped onto the pier, walked five steps, about 3.5 meters, stopped, waited for the surge to recede, remained absolutely still in the gap, then waited for the next surge, took two more steps, and retreated. The second time, he walked ten steps, about seven meters, and stopped in the western part of the middle section to feel the vibration transmission under his feet—the steel plate here was thicker than at the entrance, and the vibration transmission efficiency was slightly lower, but the difference was within the margin of error, and the baseline data could be used.

He did not reach the sinking point.

He stopped at the tenth step because he noticed something: the steel plate surface of the middle section of the pier had a larger area of ​​corrosion than he had observed on the P1 platform. About one-third of the steel plate surface had varying degrees of corrosion, and two of them were close to the critical point of corrosion. They would not break immediately under normal walking vibrations, but the critical point would arrive earlier under running vibrations or the additional weight of steel maggots.

He marked the locations of the two pieces and wrote in the memo: "Middle section, high-risk area, two locations, location: left side of the seventh node / right side of the ninth node, corrosion level: close to critical, do not step on, need to detour or confirm that there are no steel maggots attached when passing through."

Then he retreated, waited for the next surge, and walked to the thirteenth step, about nine meters, reaching the vicinity of the sinking node.

The vibration transmission characteristics of the sinking node were consistent with his prediction: the steel plate support at this location was insufficient, and an additional vibration component would be generated when the surge impacted, superimposed on the main vibration, with a frequency of about 35-40Hz, which is higher than the main vibration frequency, and a short duration of about 0.3 seconds, before dissipating.

He stepped on the left side of the sinking node, felt it once, then stepped on the right side, felt it again, and wrote in his memo: "Sinking node · Additional vibration component · 35-40Hz · Lasts for about 0.3 seconds · Superimposed on the main vibration · Does not affect the steel maggot's perception threshold (the main vibration is saturated, and the additional component is within the saturation range) · However, it will produce local vibration when stepped on during the interval, which needs to be avoided."

He returned to the P1 platform.

This time, he wrote a new line in his memo: "#003·Bridge Route·Feasibility Assessment·Completed. Conclusion: Feasible, but requires precise control of the landing point, avoiding three high-risk areas (gap/two corrosion critical points). Based on time estimation: with a wave cycle of 6.2 seconds, each wave takes 2 steps, it will take about 15 waves, or about 93 seconds."

He closed the memo and walked toward the others.

---

"I need to confirm each person's ability to pass, one by one," he said. "Not whether their ability is good or bad, but specific numbers."

He looked at Old Chen and said, "Your stride length."

Old Chen thought for a moment, "Probably sixty-five or seventy," he said, "because I have short legs."

"Sixty-five," Xie Chengzhou said. "Based on this, you take one and a half steps with each surge, requiring 20 surges, or about 124 seconds." He wrote this down in his memo and then looked at Liu Feng.

Liu Feng gave a number, “Seventy-five,” he said, “the stride length for military training.”

Xie Chengzhou nodded, "You and I are about the same, 15 surges, 93 seconds."

He collected everyone's data and arranged them in order in his memo: Old Chen, who had the shortest stride, needed the most surges, so he was placed at the front, and the people behind him didn't need to wait for him.

Then he explained the order.

"Why is Old Chen at the front of the line?" Fang Yuan asked. "He's the slowest; isn't it more dangerous for him to be at the front?"

"The slowest person goes first," Xie Chengzhou said. "That way, when the person behind him stops to wait for the wave, the person behind him can also stop and wait for the wave, keeping the rhythm in sync. If the slowest person goes last and there's no one behind him, he needs to control his own pace, but since he has no experience, he'll just follow the person in front of him. If the person in front of him has a longer stride, he'll try to catch up, and he'll keep walking in the gaps."

Fang Yuan didn't say anything more.

Old Chen said from the side, "I understand." He said, "I'll walk in front and control the pace. The people behind me will follow."

Xie Chengzhou glanced at him. "Yes," he said, "every time a wave comes, you move; when the wave recedes, you stop. No matter where the people behind you go, you stop."

Old Chen nodded, "I understand."

---

They waited for the next surge.

Old Chen stepped onto the pier.

He walked slowly, with small steps, but landed steadily, his heels firmly planted, his center of gravity low. Xie Chengzhou watched him from the edge of the P1 platform, mentally comparing each of his steps with the node positions—he walked across the gap, stepped over it, landed precisely, and didn't step on the corroded edge. The surge receded, and he stopped, standing there, feet still, waiting for the next surge.

The second surge came, and he continued walking.

After Lao Chen stepped onto the pier, Xie Chengzhou waited for a surge of waves before stepping onto it himself, following behind Lao Chen at a distance of about three steps. As he walked, his attention was divided into two places: one was the spot where he was landing, and the other was the steel maggots on the steel structures on both sides—they hadn't moved during the surge or during the lulls, clinging to the steel structures, their phosphorescence briefly brightening after the surge receded before returning to normal.

He noticed something: during the intervals, the number of steel maggots near their route was slowly increasing.

It's not clustering, it's a normal distribution change. They were already moving, just very slowly. Xie Chengzhou didn't notice this when he first observed it because the change was too small, but now that he's on the pier, he's closer and can see the change.

He kept this in his mind, but didn't write it down in his memo—he couldn't write during the surge, and he couldn't move during the lull. He simply pressed the number into his memory, intending to organize it once he reached shore.

They walked for about seven minutes.

The order in which the fifteen people passed was: Lao Chen, Xie Chengzhou, Qin Gong, Liu Feng, Hu Jian, Wu Ming, Dr. Cao, Fang Yuan, Zhang An, and Lin Xiao.

By the time Lin Xiao stepped onto the pier, they had already reached the vicinity of the entrance to the P2 platform.

Xie Chengzhou stood at the edge of the P2 platform, looking at Lin Xiao—she was the last one. The moment she stepped onto the pier, Xie Chengzhou noticed that her shoulders were shaking. It wasn't the vibration of the waves, but the shaking of her own muscles. She tried to suppress it, but couldn't. The shaking came from within.

The surge came, she took two steps, and then stopped.

The surge receded.

She stood there, her feet motionless, but her body was trembling, the tremor traveling from her shoulders to her arms, to her hands, and then to her feet—

"Lin Xiao," Xie Chengzhou said, "take a deep breath, plant your heels firmly, and wait for the next surge."

She nodded, took a deep breath, pressed her shoulders down, and planted her heels firmly.

The next surge is coming.

She took two steps and stopped. This time, her feet were firmly planted, and the shaking was less pronounced. Xie Chengzhou watched from the edge of the P2 platform, mentally calculating her position and remaining distance: she needed about six more surges, or about 37 seconds, to complete the journey.

He turned his attention back to the P2 platform and began scanning the new environment.

Platform P2 is smaller than platform P1, measuring approximately 12 by 15 meters. In the center of the platform is an equipment base that is rusted. The steel plates surrounding the base are more severely corroded than those on the trestle bridge, and about a quarter of the area is unsafe to walk on. To the north, there is a second trestle bridge connecting to platform P3. It is approximately 45 meters long, longer and narrower than the first bridge, measuring about 1.2 meters wide.

He began to develop an assessment framework for P2 in his mind.

Then he heard Lin Xiao's voice.

It wasn't a scream, but the sound of someone trying to control themselves in extreme fear but failing—a short, forced breath from the throat, followed by footsteps, not normal footsteps, but running, on the steel plate, in the gaps between the waves.

Xie Chengzhou glanced back.

Lin Xiao is running.