Chen Hao removed his finger from the confirmation box, but the notification on the screen was still lit. He didn't turn off the light or say anything; he simply turned around and saw Karl crouching on the ground, inspecting the gasket interface. His movements were slow, as if he were afraid of damaging something.

"Don't carry this alone," he said. "Let's do it together."

Karl looked up, his fingers hovering in mid-air. He opened his mouth, then closed it again, finally just nodding.

Susan was reviewing the building energy log when she heard the sound and stopped writing. Nana stood in front of the control panel, her eyes slightly blue, watching the data stream scroll across her screen.

“I’ll analyze the timing and fluctuations of the three interruptions.” Chen Hao walked to the control panel and sat down. “Can you model and predict tomorrow’s frequency points?”

“We can give it a try.” Susan turned the notebook toward him, “but we need to know if their tuning pattern is linear.”

"Nana." Chen Hao turned his head. "Check the peak records for the past seven days and see if you can find a pattern of change."

“Retrieved.” Nana tapped her finger, and a set of curves immediately appeared on the wall projection: “Increase by 0.3 Hz daily for six consecutive days, then decrease to 1.8 Hz on the seventh day, cycle reset.”

"As accurate as a clock." Chen Hao clicked his tongue. "Then what about our simulator? Which frequency band is it fixed on?"

“42.7 Hz,” Nana replied. “Dynamic response function not set.”

“So it’s hitting a wall every day.” Susan drew a simple trend line. “Tomorrow it should be around 44.5 Hz.”

“Then let’s adjust the frequency in advance.” Carl stood up. “I can write a script to let the system calibrate automatically.”

“Okay.” Chen Hao nodded. “You work on the script, Susan and I will check the data, and Nana will keep an eye on the hardware status.”

The four people gathered around the control panel, and the lights shone on the screen, illuminating several faces.

Carl opened the programming interface, and had just typed two lines of code when the alarm went off.

"Error: Parameter out of bounds." The system prompt sounded cold and impersonal.

“That’s not the parameter.” Nana glanced at it. “You used an ideal impedance value. There are losses in the actual circuit.”

“Oh.” Karl deleted and rewrote, “Then add an attenuation factor?”

"Add 0.15," Nana said, "based on the actual test data from last time."

On the second run, the script got stuck at step three.

“Still not working.” Carl scratched his head. “This thing is more troublesome than I thought.”

"Take a break first." Chen Hao patted him on the shoulder. "I just finished looking at the first round of data, and something's not right."

"What?"

“Each interruption occurred 18 seconds after the peak power supply.” Chen Hao pointed to the playback record. “It wasn’t an immediate interruption, nor was it 30 seconds later; it was always 18 seconds.”

"A coincidence?" Karl asked.

“That’s too many,” Susan chimed in. “The same thing three times in a row is unlikely to be a coincidence.”

Nana immediately pulled up three sets of data and aligned them along the timeline. The three lines on the projector were side by side, making the energy peak, system alarm, and control command flow clear at a glance.

“Eighteen seconds after the external pulse appeared, the control system determined that the power had surged,” Nana pointed out the key point, “but the actual input energy did not exceed the threshold.”

“That was a misjudgment.” Chen Hao stroked his chin. “The system thought the energy coming from outside was produced by itself, and activated the protection mechanism to cut it off?”

“The probability is extremely high,” Nana added. “The control system failed to identify external interference characteristics and treated them as internal anomalies.”

“No wonder the vibration isolation pads are only so effective.” Susan understood. “Physical isolation can only reduce vibration, it can’t change the logical judgment.”

“Then add a filter to the script.” Chen Hao looked at Karl. “Could the automatic calibration program you wrote earlier first identify that this is an external pulse before deciding whether to adjust the frequency?”

“Yes.” Carl’s eyes lit up. “Just give it a signal that it didn’t do this.”

“That’s the line of thinking.” Chen Hao smiled. “You can change the logic, and we’ll continue to verify it.”

For the next two hours, everyone was busy. Susan ran the predictive model and marked the possible resonance points for tomorrow; Chen Hao repeatedly replayed the control commands to confirm the misjudged path; Nana simultaneously updated system permissions and prepared a temporary patch.

When Carl ran the script for the third time, the progress bar reached the end without any errors.

"Did it work?" Chen Hao leaned closer.

"Preliminary approval." Karl breathed a sigh of relief. "With the addition of the feature recognition module, the system will no longer treat external pulses as internal problems."

“Next step,” Chen Hao stood up, “is to install the double-layer vibration isolation pads, and the grounding current diversion also needs to be modified.”

“The robotic arm is ready.” Nana activated the auxiliary equipment. “The installation accuracy can reach 0.01 millimeters.”

“I’ll rewire it with you,” Chen Hao said to Karl. “The high-voltage connection must be correct.”

The two put on insulated gloves and disassembled the base casing. Nana manipulated the robotic arm to precisely embed the vibration damping pad, while Susan watched the system feedback from the side.

“The pressure distribution is uniform,” she said. “The horizontal error is less than 0.5 degrees.”

"Wiring complete." Chen Hao tightened the last screw. "Check it again?"

"Verification complete." Carl checked the drawings. "No reverse connection between positive and negative terminals, and the grounding resistance meets the standard."

“Let’s give it a try.” Chen Hao took a deep breath. “Not for the result, but to see if we can make it past 8:17.”

At 2:47 a.m., the program was started for the fourth time.

The screen lit up with a green light, and the energy curve rose steadily.

The clock struck seventeen minutes past the hour.

Everyone stared at the readings.

The fluctuation was slight, but was then automatically compensated and leveled out by the system.

Eighteen seconds passed, and the alarm did not sound.

The curve continued to climb, passed the critical point, and stabilized.

"Ten minutes have passed," Susan said softly.

"Fifteen minutes." Nana updated the timer.

Ultimately, the system ran for 21 minutes before automatically ending the process and returning to normal.

The room was silent for a few seconds.

"It's really done?" Karl stared at the screen, as if in disbelief.

"It's done." Chen Hao leaned back in his chair and smiled. "It wasn't because of anyone's sudden inspiration; it was something we all worked together to achieve."

Susan closed her notebook: "We don't need to do the control experiment tomorrow."

"Let's get straight to the official procedure." Karl clenched his fist. "This time, I can take control, right?"

“Take turns,” Chen Hao said. “No one is allowed to take the blame alone, and no one should be the sole scapegoat.”

Nana pulled up tomorrow's schedule: "Task assignments have been updated. It is recommended that rest time be no less than four hours."

"I'll go to sleep later." Susan opened a new document. "I need to write down the reasons for this data discrepancy, otherwise I won't be able to explain it clearly in tomorrow's meeting."

"Write a title." Chen Hao tilted his head to watch her type. "Let's call it 'On How Underground Pipelines in Research Institutes Drive a Research Team Crazy.'"

“Too long.” Susan typed the first line. “Change it to ‘Case Analysis of Misjudgment in Control Systems Caused by External Periodic Disturbances’.”

"It's so official," Carl complained. "It has no human touch at all."

“Academic papers don’t need personal feelings,” Nana said calmly.

"Then what was the music you played just now?" Chen Hao raised an eyebrow.

“That’s an effective way to relieve cognitive fatigue.” Nana paused, “...and I also think you guys have been arguing for too long.”

The three of them were stunned for a moment, then burst out laughing.

"You're quite good at roasting people." Chen Hao shook his head. "You usually keep it so well hidden."

“I’m just stating the facts.” Nana’s eye indicator flashed. “Now, who’s going to make the coffee?”

“I’ll go.” Carl stood up. “This time I promise I won’t touch any of the equipment switches.”

He had just reached the door when his phone vibrated.

It's a message from the research institute's group chat.

Li Zhenhua issued a notification: [Tomorrow morning's 6:00 AM meeting is moved to 5:00 AM; headquarters needs to remotely access the review process.]

Carl turned around: "Hey, why did they change the time again?"

Chen Hao picked up his terminal and glanced at the updated schedule.

Before he could speak, Susan had already opened a new calculation window.

"There are only two hours left," she said. "We need to readjust the testing schedule."

Nana began to synchronize the new plan.

Chen Hao flexed his wrists.

“Then let it simmer a little longer,” he said. “The coffee was just started brewing anyway.”