“Following the book to find the horse won’t work here. The identity information can’t be trusted, but the credibility of the other information is much higher. For example, the descriptions of poisons in the letters are likely to be true. In the twelfth letter, perpetrator A said they used a type of poison that was inconvenient to administer and couldn’t be mixed into Chinese herbal medicine, which means it’s probably not a powder or granule, but most likely a liquid. Perpetrator B’s poison is different: it’s stable in composition, doesn’t easily interact with other poisons, and is probably in powder or granule form. You’re more knowledgeable in this area, so think about which poisons fit these descriptions. Prioritize poisons that are easy to obtain at your school.”

　　Fiona Bennett nodded and said, “For medical students, as long as they put their mind to it, there are quite a few poisons they can get. In fact, with some professional knowledge, you can even buy them at a pharmacy.”

　　“That’s true. To kill and to save, you need to know about the same things.” Gabriel Adams joked, but Fiona Bennett didn’t respond, just looked at the letters with a serious face.

　　When it was time for Gabriel Adams to leave, Fiona Bennett began to gather up the letters spread out on the table, one by one. She moved slowly, pausing after every few.

　　“Don’t forget to make copies of these for me. When we go out, let’s find a place nearby.” Gabriel Adams said.

　　Fiona Bennett was startled for a moment, then replied, “Oh.”

　　“What are you thinking about?”

　　Fiona Bennett sped up, quickly gathering all the letters, stacking them neatly, and handing them to Gabriel Adams. Gabriel Adams noticed her eyes were a little red.

　　“I was thinking, no matter how Susan Wright got these letters, what must she have felt when she saw them?”

　　4

　　On the way home, Fiona Bennett kept wondering what would have happened if she had opened the relics right away and discovered these letters. If the letters had been switched to deliberately mislead her into doing something, what would that be?

　　She still couldn’t figure it out. It was probably just like she’d told Gabriel Adams earlier: do nothing, keep being a pitiful snake-bird.

　　Until she ran into Frank Bishop, who was coming home from work, downstairs.

　　She would tell Frank Bishop, she suddenly realized. She would definitely tell Frank Bishop; he was her only support at the time. And after telling him, if the murderer wanted Frank Bishop to know about these things, wanted Frank Bishop to see these letters, then how would Frank Bishop react, what would he do?

　　It was all too complicated, impossible to think through.

　　Frank Bishop asked if you’d gone out, and Fiona Bennett replied with a “mm,” not saying where she’d been. Frank Bishop sensed that Fiona Bennett had something on her mind, but after three surgeries in two days, he really didn’t have the energy to probe into his wife’s troubles. He took a shower and collapsed onto the bed. When he woke up again, it was 10:30 at night.

　　Fiona Bennett was sleeping beside him, with a small light on in the living room. Frank Bishop got up carefully and walked out of the bedroom. The chair by the dining table was already pulled out. He sat down, removed the plastic food cover, and underneath were three dishes and a bowl of white rice with chopsticks resting on top. He was used to this: after working continuously, he’d come home and sleep, then wake up hungry at night, eat something, read a bit or play on the computer, and go back to sleep until morning. The dishes were boiled river shrimp, Malan greens mixed with tofu, and braised ribbonfish. Fiona Bennett was a very good cook; over the years, she had always tried hard to live well and played the role of wife very well—except for not having children. Frank Bishop didn’t reheat the food, ate slowly by himself for twenty minutes, washed the dishes, and returned to the bedroom, sitting down at the computer and pressing the power button. The fan and hard drive started to hum, and Frank Bishop heard another sound. Turning around, he saw Fiona Bennett half-sitting up.

　　“Did I wake you?”

　　“No. I wasn’t asleep.”

　　Frank Bishop saw that Fiona Bennett was just sitting there looking at him. In the darkness, he couldn’t make out her expression, so he asked what was wrong.

　　Fiona Bennett got out of bed and turned on the main light.

　　“Do you remember Susan Wright?”

　　Frank Bishop turned his body completely, sitting with his back to the computer.

　　“Of course I remember,” he said.

　　“She left me something—a xiao flute, the one she used to play all the time. I never opened it to look, but this morning I did. I found these inside the flute.”

　　Fiona Bennett opened the top drawer of the bedside table, took out the letters, and handed them to Frank Bishop.

　　Frank Bishop read through the letters twice, back and forth.

　　“Is this real?” he asked.

　　Fiona Bennett didn’t answer.

　　“I shouldn’t have seen these.” After a pause, he added, “So, among my classmates, my colleagues, there are now two murderers.”

　　He picked up the letters again, flipped through a few pages, and put them down. “Actually, I’ve thought about it. Not just me—other classmates must have thought about it too. Was Susan Wright really sick, or… But no one said anything, no one investigated, even her father didn’t say anything. Her body was cremated quickly, no autopsy was done, and that was the end of it. I didn’t expect you to bring her up again today.”

　　“What kind of person was Susan Wright?” Fiona Bennett asked.

　　“You were good friends with her.”

　　“But I only knew her for a few months.”

　　“What do you want to do?” Frank Bishop looked at his wife.

　　“I want to…” Fiona Bennett wanted to find out the truth about Susan Wright’s death, wanted to catch the two murderers who corresponded with each other, wanted to live up to her friend, to her friend’s dying wish. But she only said two words, not daring to say the rest. This was her home, and now it was just her and her husband, but she always felt as if a pair of eyes was watching her every move from behind—no, two pairs of eyes.

　　Frank Bishop shook his head.

　　“Whatever you want to do, you don’t dare say it out loud.”

　　He went out, and when he came back, he was holding an empty metal mooncake tin from Xinghualou, which they usually used to store common medicines. He put the letters inside, swept the mouse, pen holder, and other odds and ends off the table to make space, and placed the mooncake tin in the center.

　　Then Frank Bishop lit a cigarette, took two deep drags, and after half a minute, finally spoke.

　　“Our classmates are all in key positions in various departments now. Over the past six years, every one of them has worked hard. As doctors, they’re all outstanding, and they’ve saved a lot of people. Of course, saving lives as a doctor and killing Susan Wright are two different things. But as murderers, saving one more person is a bit of compensation. What I’m most worried about is, if you report this to the police now, can a case be reopened based on just these letters?”

　　He took a drag on his cigarette and looked at Fiona Bennett. Fiona Bennett said nothing. Gabriel Adams had never mentioned calling the police. He was a police officer himself, and maybe it really was hard to open a case through normal channels.

　　“It’s been nine years. If they can’t reopen the case, you’ll be putting yourself in danger again, just like back then. Even if they do reopen it, can it be solved? If not…” Frank Bishop sighed. The next words were hard to say, but he forced them out.

　　“If it can’t be solved, what will happen to you, what will happen to me? These two murderers are ruthless! When you fell into the corpse pool back then, I knew there was more to it, but I held back and never asked. Now it seems, it was them. Because you were investigating them at the time. If it weren’t for me, you’d be dead. They were capable of it nine years ago, and they’re still capable now. Back then, we didn’t know who they were, and the police couldn’t help us. We’d just be the second or third Susan Wright.”

　　Fiona Bennett’s face grew even paler.

　　Frank Bishop flicked his cigarette, and the ash fell into the mooncake tin. He glanced at it, picked up the lighter.

　　“It’s been nine years. It’s over. The living should move on.”

　　A flame rose from the lighter. Frank Bishop looked at Fiona Bennett.

　　Fiona Bennett was silent.

　　Frank Bishop set the letters on fire. Flames and smoke rose. He watched the fire, took a final deep drag on his cigarette, tossed the rest in, and let out a long sigh.

　　Fiona Bennett watched the fire grow fiercer. She thought, so this is how Frank Bishop would react if she told him. But what he said made some sense—it’s already been nine years. Nine years ago, would he have burned the letters too?

　　In any case, she decided not to tell him about Gabriel Adams for now.

　　5

　　Fiona Bennett started reading detective novels. Two a day, fourteen a week, until she felt sick.

　　She was reading for the detectives. To see how they unraveled the mysteries, layer by layer, and caught the culprit. In those novels, no matter how bizarre the case, the truth always came out in the end. But the more Fiona Bennett read, the more discouraged she became. She realized she was powerless—if she were a character in the book, she wouldn’t be able to do anything. She put herself in the detective’s shoes, pretending to be the one in the trench coat, pipe in mouth, making a casual entrance, but she couldn’t see a single clue. Only when the truth was revealed and she flipped back through the book did she see that the clues had been right there all along. From the first book to the fourteenth, she hadn’t improved at all. The fog drifted out from between the lines and trapped her; no matter how she tried to wave it away, it was useless. Fiona Bennett realized she was like the detective’s assistant in the books, or the police—characters created just to set off the protagonist. In fact, she was even worse than them!