Perhaps there is retribution in matters of the heart. If you hurt someone, another person will come and hurt you in turn. And perhaps that person truly loved you, which is why today you lose what you cherish most.

In 2020, in Yokohama, I left Tokyo just as the first snow of winter came down. The city was white from end to end, ice clinging to yellow-green treetops like tears that trembled but would not fall. The wind was sharp enough to work its way into my bones, and with that landscape and that coldness inside me, I dragged my suitcase alone to the airport. My eyes burned the whole way, yet not a single tear came. My heart had grown cold; perhaps that was why nothing in me could warm again. Running across mountains and rivers for one person is supposed to be a privilege reserved for eighteen-year-olds. And yet I, at twenty-two, a graduate student, had done exactly that for him. So what use is all that education to a girl? When it is time to do something foolish, even the most educated girl is no less foolish than anyone else. When he rejected me, he used such a clumsy excuse. He said he could not ruin me. And I had believed him. A literature graduate student who had read everything under heaven, and still I believed a reason that pompous and false. Perhaps only because he was the one I loved. His ex-girlfriend had come back. He could not be with me. He was in Tokyo while I was in Shenyang. He said there were too many objective reasons pulling us apart. I tried to believe all of it so I would not have to look at the truth: that he simply did not love me. Yokohama was utterly unlike Tokyo, warmer, damper, bustling in the same endless way and yet carrying in the air a kind of leisurely afternoon elegance. Pulling my suitcase down the street, I looked up and saw a great dark blue glass tower catching the morning sun, remote and cold. At its northwest corner stood a little pale-yellow building that belonged to an entirely different age, with a white ornamental spire and a plain sign hanging below it. I stood at the door wondering whether to go in. Then the glass swung open, and a beautiful woman smiled at me. "Hello," she said. "My name is Feng Eleven. You may also call me Dream."

In the dream, I was the daughter of a merchant family in late-1930s Yokohama. I had been living there for half a year when my father came hurrying into the garden after dinner, sweating despite the cold, and told me with eyes full of guilt and panic that he could no longer protect this household. Business had collapsed. Debts had drowned him. So he had entrusted me to Mr. Yukimura. I knew the name. A friend of my father's, though much younger, a man who had already made himself indispensable to Director Heikawa, head of the Nationalist intelligence service Black Feather Bureau. Before I could understand what my father meant, Yukimura himself stepped out and handed me a notebook containing a difficult integral. "Solve this," he said pleasantly. When I asked why I should, he drew a neat little pistol from his coat and leveled it at my father's head. "One minute," he said. "Or your father dies." I solved it in half that time. Mathematics had always been my one true talent, even in my former life. Yukimura glanced at the page, smiled, and said my thinking was clear enough. He would take me. It turned out he was building a training class to specialize in codebreaking. Because my mathematics was good enough, he had chosen me by force. A few days later he took me away to the mountains. On the night train I almost fell in the narrow corridor and landed instead against a warm chest that smelled faintly of sun-warmed quilts in winter. When I looked up, I saw a face with a completely different bone structure and skin tone from Yo Ishikawa's, and yet in that instant I still found in it the same brows, the same eyes, the same chill reserve. He said nothing at all, only steadied me and moved past. Later I learned his name: Yo Kondo, a genuine mathematical prodigy and one of the best students in the class.

The training camp was hidden in deep mountains. The coursework was punishing, ten or more hours a day, with nightly exams so brutal that the student who placed last had to kneel in public on the icy flagstones. Under that pressure, Yo Kondo and I began quietly taking turns at first place, just as once, in another life, Yo Ishikawa and I had competed over Olympiad mathematics. It was dangerous, the way Kondo's eyes and name and entire indifferent air kept reminding me of the man I had once loved, but danger does not always stop desire. Perhaps that was why I kept finding excuses to brush against him, to ask him to fetch me a book or explain a problem, though he was so cool that he could not even remember my name half the time. Aya Akiyama, my roommate, noticed him too. She was beautiful enough to be a film star and fragile enough to tell him, under the evening trees, that life in the camp was too hard for her to bear alone. Kondo did not even look properly at her. He glanced at her exercise book and told her that Mori Wakane's solution would be simpler, and that since we were roommates, she ought to ask me. Watching him walk away from her without a backward glance, I thought of all the women who would stand at a distance, hurt and bewildered, behind a man like him.

One evening I returned to the dorm room and found a figure on the balcony that I thought at first was Aya. We had both spent too much time being foolish over men, and I said so out loud, rambling about how even the smartest women become idiots before the men they love. I spoke of how painful it is to like someone cold and self-absorbed, someone whose thoughts you can never read, even when you are beside him. Only after I had said all of it did the balcony door open and reveal not Aya, but Yukimura, in a pale blue gown, smiling as though he had heard every word. He came close enough that I had to spring upright from the bed, only to end up nearer him than before. He tilted up my chin and said that I was right: liking someone is painful. But what did private love matter in times like these? Then he ordered me to pack. The next assignment would take me to occupied Kyoto. The Sixth Station there needed skilled codebreakers, and he had recommended me personally. When I protested that Kyoto was under a puppet government and far too dangerous, he simply pointed out that danger was why I had been trained in the first place. I gave in and packed. Then, just before leaving, he decided to "test" me. He kissed me with sudden violence, ripped at my collar, and when I slapped him he only smiled and asked whether I thought I could really survive spy work if even that overwhelmed me. I was furious until I realized he meant to teach, to force me to understand how often a woman's body becomes a weapon in such work. When he kissed me again, more slowly, I went cold and strategic, kissed him back, and then whispered in his ear that if this was the lesson, then I had learned it. For a second he looked wounded. At that exact moment Aya returned and stood in the doorway, frozen, as if what she had seen had rewritten something inside her forever.

Kyoto, under occupation, was still beautiful and yet full of a gloom that no clear sky could drive off. I was inserted into the Sixth Station under a new identity as Bai Yun'er, supposedly a woman from Sichuan who had studied abroad. The work was intense but manageable, especially because the Morse systems used there happened to be among my strengths. A year later a new arrival entered the station. Darker skin, fine lips, the same unreadable eyes. Yo Kondo. Under his gray suit he looked so sharply familiar that for a moment I forgot to breathe. He slipped me a coded note telling me to meet him at seven in the Red Rose Café. There, after making sure we had not been followed, he told me the arrangement from above: officially he had been sent to pursue me, and in time to court me, marry me, and become my husband. Two employees of the Sixth Station joined as a couple would attract less suspicion. Besides that, a group of underground agents had entered Kyoto to assassinate collaborators and militarists. Our task was to shield them. I was still reeling from the absurdity of being told to let a man who looked and felt so much like my old love pretend to love me when an exquisitely dressed woman arrived with a middle-aged man on her arm. It was Aya Akiyama. Kondo pressed my head lightly against his shoulder and murmured that I was not to keep looking, that in occupied Kyoto old classmates could only ruin one another if they recognized too much. Then he told me, almost playfully, that from this moment on he would begin to pursue me.

The pursuit was supposed to be a performance. He sent red roses to my desk. He held my hand just long enough for the station's secretaries to start smiling knowingly. When our eyes met across the office, my face still heated against my will, though I knew every move had an official purpose behind it. Then the station chief called an emergency meeting. The deputy director, newly arrived from Japan, had been murdered before even taking office. His face on the newspaper was one I recognized at once: the middle-aged man who had entered the café with Aya. The chief raged that a female underground agent from the Qingpu training system was responsible and ordered all of us to find her within three days. Kondo and I knew immediately that the assassin had to be Aya. Using what influence we had, we delayed and diverted what information we could. But the Sixth Station's network was vast. Before long I found the address in a file: Jinjiang Road, Number Thirty-Six. The station chief was preparing to seal off the whole district. If military police got there first, Aya would die without even the dignity of a trial. I lured Kondo out to the little garden behind the office. He said at once that he would go save her while I delayed the transmission of the orders as long as possible. I caught his sleeve in panic and begged him not to go. He looked at me strangely and asked why I cared so much. Then, with the autumn evening burning around him, he said with rare seriousness that he had never liked competing with anyone and never liked making false feelings look true. But with me, he had gone and grown sincere. It was one of those instants that shatter a whole life cleanly in two.

Even though I did everything I could to delay the station chief's orders, they went out anyway. Kondo never came back. I sat awake for two nights and three days without sleep. At last my room door opened in the middle of the night, and I jumped up, convinced it was him. Instead it was Yukimura. His face, usually so composed, was cold and grave. I rushed to him barefoot and demanded news of Kondo, who had gone to help Aya and disappeared. Yukimura lashed out, asking who had given us permission to act on our own, whether losing Aya was not enough without losing the two of us as well. I shouted back that protecting the assassins had come from above, so how could rescuing her be wrong? Why was he wasting breath arguing instead of saving them? He stood there in silence a long time, then asked whether I had any idea what I looked like. Barefoot, hair loose, eyes full of sleepless blood, I must have looked half-mad. He said that what he had feared most had happened: Kondo had been placed near me and I had fallen for him anyway. He said he had never wanted to do that, never wanted to watch me give my heart to another man. Then, just as quickly, he gathered himself again. Kondo had failed to save Aya. His cover was blown. Orders had come from above: I was to preserve myself at any cost and sever every visible connection to him. I finally began to cry. Yukimura held me and said that in this age of war, private love truly amounted to nothing. The worst thing was not always watching someone die. Sometimes it was watching him live long enough to be tortured first.

I became the note-taker for Kondo's interrogation. The so-called interrogation room of the Sixth Station was simply a torture chamber. There was no cruelty there that had not already been imagined by someone. The chief wanted to determine what Kondo and I were to each other, and so he sat me there to write the record. Kondo was covered in wounds. His handsome face had collapsed into exhaustion, and I sat across from him with my own face frozen, my heart so ruined with pain that it had gone numb. The chief lied to him and said Aya had already confessed everything. Kondo raised his head for the first time and said coldly that she would never do that. Then he looked at me once, quickly, and said that there is retribution in love: when you hurt someone, another person comes to hurt you, and perhaps because that person truly loved you, you end up losing the one you cherished most. Only I understood what he meant. He was telling me that the one he treasured was me. Yukimura's voice echoed in my mind, insisting again that in times like these, private love was worthless. I stood and said to the chief that I knew where the information he wanted was hidden. There was a shirt at Kondo's place, I said, and inside the stitching of the collar a list had been sewn in Morse code. While the chief hesitated, weighing whether to believe me, I grabbed the pistol at his waist and shot every puppet official in the room. Blood filled the air. Kondo was barely conscious. Cradling his face in my hands, I smiled through tears and told him that if there was another life, he should stay far away from me, because loving someone is too painful. Before I could finish, the senior officials who had been monitoring from the next room burst in with guards. Several shots rang out. Heat blossomed in my chest like a red lotus opening all at once. As I fell, still holding his hand, I found myself laughing and crying together. If there is another life, I asked the dark as it closed, could I please not love you again?