Translator: Nyoi-Bo Studio Editor: Nyoi-Bo Studio

Song Jinning was a scientist, and behaved like one. She pointed to a web page on the computer screen. “I just checked. There still hasn’t been a breakthrough in graphene extraction technology, after all these years, which means it isn’t possible to mass produce this battery.”

As soon as Gu Nianzhi heard that it required years of polishing and refining by hand to obtain a tiny sliver of graphene material, she immediately put the brakes on her enthusiasm. “Oh well, forget I asked. I didn’t know it was so troublesome.”

“It’s a lot of trouble, yes.” Song Jinning nodded. “And it was pure luck that Huo Guanyuan found a graphite ore with a special molecular structure during one of his missions. It was a lot easier to separate single-layer graphene from that ore’s surface. He gave that ore to my father as a gift, and my father gave it to me. I sanded the ore by hand during my free time, and that was how I obtained high quality single-layer graphene crystals from it.”

Gu Nianzhi listened to the explanation, but understood very little of it. Her eyes turned into tiny spirals yet again.

She kept the smile on her face as she struggled to pay attention to what Song Jinning was saying. By the end of Song Jinning’s explanation, Gu Nianzhi had arrived at two conclusions.

One: Huo Guanyuan found a graphite ore with a special molecular structure.

Two: Song Jinning used the materials refined from the ore to make a mobile phone battery. She then gave the battery to Huo Guanyuan as a present.

Song Jinning had therefore returned the ore to its original owner, in a way.

It seemed much more likely for someone to be interested in the battery, rather than the phone itself.

Gu Nianzhi sat next to Song Jinning, pretending to be interested in the graphene molecular formula Song Jinning was now showing her. In actual fact, her brain had already took off for outer space.

There had not been a major breakthrough in graphene extraction technology in the last 10 years—that meant that whoever stole the phone had not been able to replicate Song Jinning’s success with the battery.

It also showed that the thief was most likely unaware that the graphite ore with the special molecular structure had been the key to Song Jinning’s success.

“Auntie Song, do you think it’s possible someone committed murder just to get their hands on this mobile phone battery?” Gu Nianzhi cocked her head as she stared at the mathematical formula and molecular formula Song Jinning had pulled up on the computer screen.

Song Jinning considered it. “This battery would be extremely valuable when coupled with a breakthrough in graphene stripping technology, and many men have done dastardly things just for money. But you have to remember that there hasn’t been a breakthrough in the technology, so I don’t believe anyone would resort to murder, just yet.”

“…But it’s possible she simply didn’t have all the information…” mused Gu Nianzhi as she tried her best to get inside the killer’s head. “Maybe she thought you’d had a major breakthrough, and that was what drove her to take the risk and steal the phone. It was all for nothing, of course.”

Song Jinning smiled as she shook her head. “If you’re implying it was Bai Jinyi, well, I don’t think she would have done something like that. She’s a scientist, too, and she knew I made the battery. If she wanted to steal the technology behind the battery, she would have done it a long time ago.”

It made no sense for her to wait until six years after the laboratory accident to murder someone for it.

“Oh? So she knew you made the battery? That means she must have known you used special graphite ore for it, right?”

“Yes, that’s right.”

Gu Nianzhi rested her head on Song Jinning’s shoulder, too confused to speak.

She had to admit that she was probably on the wrong track.

Was Bai Jinyi not the murderer, after all?

Or was Bai Jinyi the murderer—only she had taken Huo Guanyuan’s personal phone for some other purpose?

Gu Nianzhi’s fingers tapped out a slow, erratic rhythm on Song Jinning’s computer desk as she mulled it over. What possible reason was there for Bai Jinyi to be driven to murder and theft after six years?

…

After leaving Song Jinning’s room, Gu Nianzhi went to Huo Shaoheng’s office with her laptop instead of returning to her room.

It was already night, but the lights in the office building were on.

The staff in the office building worked in 8 hour shifts. That meant there was always someone in the building, 24 hours a day, 365 days a year.

Huo Shaoheng and his men often went several days without sleeping.

“Back again, Nianzhi? Are you looking for a good thrashing?” Zhao Liangze rolled up his sleeves and walked over with his best impression of an “evil smirk.”

Gu Nianzhi played along by putting on her “oh no I’m so scared” expression. She slipped into Huo Shaoheng’s office, quick as lightning, and locked the door. She shook a triumphant fist at the door and Zhao Liangze, who was now standing before it.

Zhao Liangze made a few half-hearted gestures at the door, before giving up.

He was just teasing Gu Nianzhi, anyway.

Gu Nianzhi turned and saw Huo Shaoheng seated behind his desk. The bright ceiling light shone upon him from up above, bringing out the shadows on his handsome face. He was as perfect and beautiful as a Greek statue.

Huo Shaoheng’s eyes were glued to his computer screen; his fingers flew over his keyboard as he typed confidently and quickly. There was a pair of closed headphones over his ears, and he appeared to be talking to someone through his mouthpiece.

“You’re here.” Huo Shaoheng greeted her without looking up from his computer screen. “Sit down.”

Gu Nianzhi sat in the sofa area in the middle of Huo Shaoheng’s office.

She placed her laptop on the coffee table. As she did so, she made funny faces in the direction of the transparent wall in the office.

But the people outside could not see her, or anything else inside the office. It was a one-way mirror, just like the wall in the interrogation room.

Gu Nianzhi had realized this when she was outside the office, which was why she was now boldly pulling funny faces at the one-way mirror.

Huo Shaoheng finally ended his call and closed the computer program. When he looked up, he saw Gu Nianzhi making shadow animal puppets on the opposite wall with her porcelain-white hands and the light shining from the other end of the room.

Little ducklings that ran excitedly about, proud giraffes, barking puppies—she was obviously enjoying herself.

Huo Shaoheng got up from behind his desk and sat beside her. He asked, “Have you spoken to my mother?”

Gu Nianzhi nodded. She stopped making the shadow puppets and rubbed her hands before opening up the web page on graphene. She showed it to Huo Shaoheng. “I asked about that amazing battery, and I get how it works now.”

Huo Shaoheng quickly read the contents of the web page. He shook his head. “I don’t think Luo Xinxue was killed because of the battery.”

“But what does the murderer want with the phone, then?” Gu Nianzhi could not figure it out. “If the phone went missing when Luo Xinxue died, that would have been six years after the laboratory accident involving Huo Guanyuan and Auntie Song.”

“Well, there’s another possibility. Maybe the phone was already missing before Luo Xinxue’s death, but no one realized it,” Huo Shaoheng pointed out. “Don’t think too much about it. We don’t need to know why the murderer took the phone. We only have to prove that Luo Xinxue’s killer stole it from her.”

Gu Nianzhi immediately understood. “I get it now. I shouldn’t get ahead of myself.”

It was much easier to find the right strategy if they focused on one simple question: where was the phone now?

…

The next day, the telecommunications company sent them the communications record for Huo Guanyuan’s private mobile number.

Under normal circumstances, most telcos would turn down requests to see records from so many years ago. It was just too much work to dig up old records.

But there was a court order, and pressure from the military on top of that. The company was left with no choice; they had to hand over the records.

The telco printed out the full communications record for Huo Guanyuan’s private phone. It spanned over two decades.

Unfortunately, the records showed that the phone had rarely been in use.

Gu Nianzhi saw from the records that the mobile number had been registered under Huo Guanyuan’s name for about five years, but the call records did not go beyond 10 pages. The number had also been used to send a few text messages, but all the messages proved to be irrelevant.

The records came to an abrupt end 16 years ago—the day of the laboratory accident.

From that day on, the phone waited in vain for its owner.

The records also showed that Luo Xinxue had not used the phone—not even once—after the phone was handed over to her as part of her deceased husband’s belongings.

The phone had remained silent for 6 years when Luo Xinxue met her untimely death. What was so special about it, for someone to resort to murder and theft just to get their hands on it?

Gu Nianzhi spent virtually every minute of every day thinking about it. She lost all her appetite, and spent her nights restlessly tossing and turning in bed—but she could not come up with a plausible answer.

Zhao Liangze saw the agony Gu Nianzhi was going through. Finally, he could stand it no longer. He pulled her out from Huo Shaoheng’s office, and seated her before his own computer. “I want you to run a program for me. We only have one more day before the next hearing. If we can’t get our act together by then, Bai Jinyi’s lawyer may actually succeed in getting Bai Jinyi off the hook, especially if they’ve found flaws in Huo Jialan’s story.”

Gu Nianzhi gave a cold, mirthless chuckle. “Bai Jinyi, proven innocent in Luo Xinxue’s case? Over my dead body! And besides, there’s still Auntie Song’s case!”