Zheng Yun, Bai Jin, and Shi Hao had each gone out with their own people to search for leads.

Yan Qing looked at E’Yuan and said, “We shouldn’t be idle either. Let’s go over Song Zixian’s body one more time.”

Without Shi Ting, the Military Police Division was like a ship without its captain — yet it showed no signs of grinding to a halt. On the contrary, each person, driven by a determination to find the truth, worked with fierce and energetic purpose.

Shi Ting had already laid the groundwork. What remained was for them to build the road properly, and see it through to completion.

By midday, Bai Jin was the first to return. He had been busy all morning without so much as a sip of water, and upon spotting a thermos on the desk, he snatched it up without a word and poured it straight into his mouth.

“Found it.” Bai Jin wiped the water from the corner of his mouth, his eyes shining. “I found the suspect’s fingerprint.”

Yan Qing and E’Yuan heard his shout and crowded around excitedly.

“Miss Yan was absolutely right — after killing Song Zixian, the killer went through a process of cleaning himself up, and in doing so, he removed his gloves.” Bai Jin held up the evidence bag he had been shielding with great care. “Not only did the killer wash his face, he also used Song Zixian’s toothbrush cup. I lifted a fingerprint from the cup that does not belong to Song Zixian.”

“That’s wonderful.” E’Yuan let out a cheer. “All we have to do now is compare that fingerprint against Minister Han’s, and we’ll know whether he’s the killer.”

Yan Qing frowned, less optimistic. “But how do we obtain Han Qiren’s fingerprints? With Shi Ting gone, no one has any means of getting close to Han Qiren.”

The question immediately stumped everyone.

Han Qiren held great power and authority, and even Shi Ting had been unable to corner him — how much less could anyone else in the Military Police Division? Getting his fingerprints would be like pulling a tooth from a tiger’s mouth.

Bai Jin scratched his head. “What if we ambush him, throw a sack over his head, knock him out, and press his hand down for a print?”

E’Yuan’s eyes went wide. “Are you out of your mind? Assaulting a senior government official is a serious crime. Instead of catching anyone else, you’d end up catching yourself.”

“I was joking.” Bai Jin naturally knew that idea was out of the question — and besides, Han Qiren always had bodyguards at his side; getting anywhere near him was easier said than done.

“Han Qiren’s fingerprints? I have them.” A bright, clear voice came from the doorway, and Zheng Yun appeared before everyone, carrying a leather bag.

“Shu Shi, what did you find?” Bai Jin rushed forward to meet him.

“Hold on — let me have some water first. My throat feels like it’s on fire.” Zheng Yun set the bag down on the table, from which came a rattling, clattering sound.

Bai Jin quickly poured him a cup. “Drink, drink, quickly.”

Zheng Yun drank, then composed himself before speaking. “On the night of the 10th, there were four people at the mahjong table with Han Qiren in total.”

“Five people playing mahjong, with one watching?”

“It started as Han Qiren, the Deputy Minister of Internal Affairs, and two advisors. But sometime after nine o’clock, Han Qiren said he had a headache and went to the bedroom to sleep. Secretary Hu from the Secretariat took his place at the table, and the others played through until daybreak.”

Bai Jin’s eyes lit up. “So that means Han Qiren had no alibi from after nine o’clock on the night of the 10th until the following morning.”

“According to Secretary Hu, when they were leaving in the morning and wanted to say goodbye to Han Qiren, they walked to his door and heard snoring coming from inside his room.”

“Was Han Qiren still inside — or had he already returned? What time was it?”

“Seven o’clock.”

Bai Jin quickly ran the numbers in his head. “Liu Cui discovered Song Zixian’s death at six thirty-five in the morning. When she went downstairs to make a phone call, the killer followed her out of Song Zixian’s home. Twenty-five minutes would have been more than enough time to travel from Song Zixian’s house to the residence where Han Qiren was staying.”

“And wasn’t Han Qiren worried they might end the game early and discover he wasn’t in his room?”

“He must have locked his door from the inside. Those people would never have disturbed him lightly. Besides, every time they played mahjong through the night, they always finished after seven in the morning — because the steamed bun shop at the corner started serving at seven twenty, and wrapping up the game with steamed buns was an unbreakable tradition.”

Bai Jin suddenly remembered. “You said you got Han Qiren’s fingerprints — where are they?”

“Right there in the bag.”

Bai Jin tore it open with eager hands, and with a clatter and a rattle, a heap of mahjong tiles spilled out.

A grin broke across his face. “As long as Han Qiren played mahjong, he would definitely have left fingerprints on the tiles. All I need to do is lift every fingerprint from the tiles, and whichever one matches the print on Song Zixian’s toothbrush cup is the killer’s.”

“Exactly.” Zheng Yun clapped him on the shoulder. “Go.”

After Bai Jin left, Yan Qing found herself very curious about how Zheng Yun had managed all of this. By rights, the people at that mahjong table were all senior officials — they would never have submitted to a direct investigation by Zheng Yun, especially one connected to Han Qiren.

“Zheng, you stole those mahjong tiles, didn’t you?” E’Yuan guessed with a laugh.

Zheng Yun explained, “Seventh Brother said to use extraordinary measures when necessary. I looked into it and found that Secretary Hu from the Secretariat keeps a woman on the side. His wife comes from a prominent family and has a fierce, unyielding temper — Secretary Hu is terrified of her. I used that woman as leverage, and after that he answered every question without hesitation. The mahjong tiles were something he borrowed from Han Qiren’s household. The servants there assumed he wanted them for a game and handed them over without a second thought. Once Bai finishes the fingerprint comparison, I still need to return them — otherwise Han Qiren will grow suspicious.”

At the mention of Shi Ting, Yan Qing could not help feeling a quiet ache. She knew he was only under house arrest in his own courtyard, and yet she still worried about his injury.

Was he taking his medicine on time? Was he changing the gauze on his wound? That man — always so careless with himself, yet so meticulous about everything that concerned her.

“The results are in.” Bai Jin burst into the office, waving a slip of paper in his hand. “Six fingerprints in total were lifted from the mahjong tiles. One of them is a match for the print on Song Zixian’s toothbrush cup.”

“Wonderful.” E’Yuan slapped the table with delight. “The killer really is Han Qiren.”

Yan Qing, however, furrowed her brow. “Even though the fingerprints match, Han Qiren is no ordinary person. What if he argues that he left them there on a previous visit to Song Zixian’s home?”

“True.” Zheng Yun gathered the mahjong tiles. “If this were an ordinary person, we would have made the arrest by now. But Han Qiren is the Minister of Finance — we can’t even get close to him. Even if we went to arrest him, his bodyguards would never allow us to take him.”

“So we still need that agreement.” Yan Qing touched her lips lightly. “Han Qiren and Song Zixian stored a fingerprint-coded safe in a bank’s safety deposit box. They must have signed an agreement with the bank when they did so. Only by finding that agreement, and then finding that safe, can we nail down his guilt beyond any possibility of rebuttal.”

“But where is that agreement?” Bai Jin’s cheerful face fell into a grimace. “I’ve already turned Song Zixian’s home practically inside out.”

“What about his office?” Yan Qing reminded him.

“I searched the office too. Nothing.”

Yan Qing thought for a moment. “If I had something truly important, I would keep it somewhere I could see every day. Since it isn’t at home, it must be at the office. Song Zixian arrives at the bank at eight in the morning and leaves at five in the evening — the majority of his waking hours are spent in his office. And his office is inside the bank itself. No one knows the bank’s security system better than he does. Keeping it there is safer than anywhere else.”

Bai Jin nodded in agreement. “Then let’s make another trip to his office. I refuse to believe we can’t dig up what we’re looking for, no matter how deep we have to dig.”

“I’ll come with you.” Yan Qing looked at Zheng Yun. “Zheng, you’d better hurry and return the mahjong tiles — don’t let Han Qiren grow suspicious.”

“Understood.” Zheng Yun gave Yan Qing a long, searching look.

He had met her before anyone else had — at the scene of the Chen family murder case, where she had been holding a flashlight, speaking to Seventh Brother with total confidence and ease.

At the time, like Seventh Brother, he had been struck with astonishment at her analysis. She was two years younger than himself, yet she carried a maturity that seemed entirely out of step with her age.

As time passed, the feeling she gave him had come to resemble Seventh Brother more and more. Whenever she was present, it was as though there was a guiding pillar in their midst.

He used to wonder often what kind of woman would ever be worthy of the man he admired most. Looking at it now, it seemed clear — among all the rivers in the world, the only one who could bring Seventh Brother to his knees was Miss Yan.

—

Bai Jin and Yan Qing made their way once more to Zhongqi Bank.

After Song Zixian’s death, the deputy director had temporarily taken over his duties. The former director’s office was sealed with police tape — until the case was closed, the tape could not be removed.

Bai Jin exchanged a few words with the deputy director, who, having long grown accustomed to such visits, simply waved them through. Since the incident, the Military Police Division had nearly worn a groove into the office doorstep.

Bai Jin pushed Yan Qing’s wheelchair into Song Zixian’s office.

It was a spacious private room. Just inside the entrance stood several potted plants that, having gone untended for days, had turned mostly yellow. To the left was a row of black sofas and a glass coffee table; to the right, a wide desk, and behind it a row of bookshelves packed tightly with volumes.

Every spot in this room where something could be hidden, Bai Jin had already searched multiple times.

“Did you check the bookshelves?”

“I did.” Bai Jin replied. “The shelf divisions are very narrow — only wide enough to hold books. There wouldn’t be room for a file folder or anything like that.”

“Did you go through every book, every page?”

“That I didn’t. Would Song Zixian really be cautious enough to tuck something that important between the pages of a book?”

“Regardless of whether it seems possible, it must be checked.” Yan Qing wheeled herself in front of the shelves, took down a book, and began turning through it page by page with care.

“Miss Yan is right.” Bai Jin found his drive renewed and pulled out several books to look through as well.

Working from either end toward the center, the two of them searched with enough thoroughness that not a single inserted page was overlooked. Yet the result was exactly as Bai Jin had said — Song Zixian had not hidden anything among the pages.

With only a few books left to go, Bai Jin began to lose heart. “It seems like there’s really nothing here.”

“This book — why won’t it come out?” Yan Qing reached up for a thick, dark green hardcover book. The book was not large, but it was substantial.

Bai Jin came to help, and found himself equally unable to move it. When he tried rotating it left and right, there came a creak, and a small door on the adjacent shelf sprang open.

—