Once We Lived in Nanjing

January 1, 2041, 10:20 PM, 4 hours before the nuclear missile is expected to unlock.

"BG, I'm in position." Ban Xia gasped, kneeling on the ground, wiping the sweat off her forehead, holding the walkie-talkie on her backpack strap, "I have a bad feeling, that thing might be nearby, I need to speed up."

"Received, be cautious, make it quick." Bai Yang's voice came from the walkie-talkie, "Have you found it? Miss, OVER."

Ban Xia successfully located Miss Qiu, who was still in the same place as when she last came to find her. Covered in dust and debris, lying amidst rubble, the object had been lying here untouched for many years, resembling a rock.

The girl took out the key from her pocket, bit off the plastic seal with her teeth, and touched the control window on the nuclear missile.

"I'm about to insert the key."

Ban Xia forcefully inserted the key into the slot, then pressed her ear against it. After a few seconds, she tapped the missile like slapping a watermelon, then pressed her ear against it again. This time there was a sound. Through the composite casing, she could hear a humming noise inside the missile, like a motor running, followed by more complex sounds: metal friction, the buzzing of a buzzer, and the timer starting to work—the long-silent nuclear missile was gradually reawakening.

It was a success, the girl was surprised, the key worked.

Next, she needed to enter the code.

"Miss, only you know the code."

It was that phrase again.

Everyone told her only she knew the code, but Ban Xia was clueless. How could she know what the code was for this missile?

Touching the six-digit mechanical code wheel, Ban Xia furrowed her brow. Which six digits could it be?

Someone's birthday?

Or some secret code?

While thinking, the girl carefully turned the dials of the code wheel, observing the numbers in the moonlight.

Suddenly there was a 'click,' and Ban Xia startled.

She found the wheel she was pushing got locked, stopping at the number "8", and no matter how much she pushed, it wouldn't budge. Ban Xia was a bit shocked; she immediately tried to turn the second wheel, which rolled to the number "0" and there was another 'click,' it locked again.

Ban Xia described the situation to Bai Yang, who was equally astonished.

"Clearly, the code is generated only after the key is inserted; before inserting the key, this code doesn't exist at all. That's why people from Zhonghe Industry said that only one person knows the code." Zhao Bowen was standing behind Bai Yang, his hands resting on a chair's backrest, "That person is the one who inserted the key."

Bai Yang's eyes widened.

"Manual input of the code is just for manually confirming unlocking of the missile, which is an irreversible process; once started, it cannot be stopped." Zhao Bowen continued, "As I've told you before, this missile was designed to avoid using precise microelectronic structures; many features had to be accomplished through crude methods."

"Crude methods?" Bai Yang turned his head.

"Yes, crude methods, very basic, beyond your imagination, like its safety mechanism. You might think it uses some advanced encryption algorithm, but in reality, it uses a spring." Zhao Bowen explained, "Yes, just like the spring used in winding clocks. According to Zhonghe Industry, when designing this part, they were only left with a two-centimeter square space. They needed to design a safety mechanism in such a small place, and the whole team was so distressed they couldn't sleep. Eventually, someone noticed their child's spring toy at home and had a brainwave to use it."

"How does the spring work?"

"They use a tightened spring to lock the key slot. The spring is made of a special alloy, tightly wound to take many years to unwind." Zhao Bowen explained, "The safest measures are often purely physical, blocking the slot until the set time arrives, preventing external insertion."

At this moment, the girl's voice came through the earpiece:

"BG, all codes have been entered."

"Code entry complete." Bai Yang repeated.

Zhao Bowen clenched his fists tightly. He wasn't the only one waiting for news; everyone was waiting for the news that would come twenty years later. They were even more tense than the last long-five launch, as the entire team had been working overtime for many days just for this moment.

All six mechanical code wheels got locked; the final code generated was 802547.

Ban Xia breathed a sigh of relief; the control window's red "disconnect" turned green "connect," indicating the missile was successfully unlocked.

"BG, unlock successful."

The current time was 10:25 PM.

The actual unlock time of the nuclear missile was only three hours different from the planned unlock time by the Command Center. Old Zhao and his team had set a very accurate timetable.

"Now leave there, Miss. The unlocked missile will enter the ready-to-trigger state in six hours." Bai Yang's tone was steady, "You have six hours to complete all subsequent tasks, then evacuate to a safe zone, OVER."

"Received."

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Back at Meihua Villa, Ban Xia needed to switch the radio's data link to the two wireless cameras at Xinjiekou, transmitting the video data captured by the cameras back to the Nanjing Command Center in 2020. The night before, they had already tested the cameras, which were quite unstable, with intermittent signals, on and off. But at this time, nobody could expect better results; they had to make do with what they had.