Aside from the Lake Motosu Incident and the incident involving the NHK fee collector, Aomame clearly remembered the other events and incidents and accidents that had occurred at the time, and she clearly remembered having read all the newspaper reports about them. Only in those two cases did her powers of recall seem to fail her. Why should that be? Why should there be absolutely nothing left in her memory from those two events alone? Even supposing this is all due to some malfunction in my brain, could I possibly have erased those two matters so cleanly, leaving everything else intact?

Aomame closed her eyes and pressed her fingertips against her temples—hard. Maybe such a thing is, in fact, possible. Maybe my brain is giving rise to some kind of function that is trying to remake reality, that singles out certain news stories and throws a black cloth over them to keep me from seeing or remembering them—the police department’s switch to new guns and uniforms, the construction of a joint U.S.-Soviet moon base, an NHK fee collector’s stabbing of a college student, a fierce gun battle at Lake Motosu between a radical group and a special detachment of the Self-Defense Force.

But what do any of these things have in common?

Nothing at all, as far as I can see.

Aomame continued tapping on her teeth with the top end of her ballpoint pen as her mind spun furiously.

She kept this up for a long time until finally, the thought struck her: Maybe I can look at it this way—the problem is not with me but with the world around me. It’s not that my consciousness or mind has given rise to some abnormality, but rather that some kind of incomprehensible power has caused the world around me to change.

The more she thought about it, the more natural her second hypothesis began to feel to her because, no matter how much she searched for it, she could not find in herself a gap or distortion in her mind.

And so she carried this hypothesis forward:

It’s not me but the world that’s deranged.

Yes, that settles it.

At some point in time, the world I knew either vanished or withdrew, and another world came to take its place. Like the switching of a track. In other words, my mind, here and now, belongs to the world that was, but the world itself has already changed into something else. So far, the actual changes carried out in that process are limited in number. Most of the new world has been retained from the world I knew, which is why the changes have presented (virtually) no impediments to my daily life—so far. But the changes that have already taken place will almost certainly create other, greater, differences around me as time goes by. Those differences will expand little by little and will, in some cases, destroy the logicality of the actions I take. They could well cause me to commit errors that are—for me—literally fatal.

Parallel worlds.

Aomame scowled as if she had bitten into something horribly sour, though the scowl was not as extreme as the earlier one. She started tapping her ballpoint pen against her teeth again, and released a deep groan. The high school student behind her heard it rattle in her throat, but this time pretended not to hear.

This is starting to sound like science fiction.

Am I just making up a self-serving hypothesis as a form of self-defense? Maybe it’s just that I’ve gone crazy. I see my own mind as perfectly normal, as free of distortion. But don’t all mental patients insist that they are perfectly fine and it’s the world around them that is crazy? Aren’t I just proposing the wild hypothesis of parallel worlds as a way to justify my own madness?

This calls for the detached opinion of a third party.

But going to a psychiatrist for analysis is out of the question. The situation is far too complicated for that, and there’s too much that I can’t talk about. Take my recent “work,” for example, which, without a doubt, is against the law. I mean, I’ve been secretly killing men with a homemade ice pick. I couldn’t possibly tell a doctor about that, even if the men themselves have been utterly despicable, twisted individuals.

Even supposing I could successfully conceal my illegal activities, the legal parts of the life I’ve led since birth could hardly be called normal, either. My life is like a trunk stuffed with dirty laundry. It contains more than enough material to drive any one human being to mental aberration—maybe two or three people’s worth. My sex life alone would do. It’s nothing I could talk about to anyone.

No, I can’t go to a doctor. I have to solve this on my own.

Let me pursue this hypothesis a little further if I can.

If something like this has actually happened—if, that is, this world I’m standing in now has in fact taken the place of the old one—then when, where, and how did the switching of the tracks occur, in the most concrete sense?

Aomame made another concentrated effort to work her way back through her memory.

She had first become aware of the changes in the world a few days earlier, when she took care of the oil field development specialist in a hotel room in Shibuya. She had left her taxi on the elevated Metropolitan Expressway No. 3, climbed down an emergency escape stairway to Route 246, changed her stockings, and headed for Sangenjaya Station on the Tokyu Line. On the way to the station, she passed a young policeman and noticed for the first time that something about his appearance was different. That’s when it all started. Which means the world switched tracks just before that. The policeman I saw near home that morning was wearing the same old uniform and carrying an old-fashioned revolver.

Aomame recalled the odd sensation she had felt when she heard the opening of Janáček’s Sinfonietta in the taxi caught in traffic. She had experienced it as a kind of physical wrenching, as if the components of her body were being wrung out like a rag. Then the driver told me about the Metropolitan Expressway’s emergency stairway. I took off my high heels and climbed down. The entire time I climbed down that precarious stairway in my stocking feet with the wind tearing at me, the opening fanfare of Janáček’s Sinfonietta echoed on and off in my ears. That may have been when it started, she thought.

There had been something strange about that taxi driver, too. Aomame still remembered his parting words. She reproduced them as precisely as she could in her mind:

After youdosomething like that, the everydaylookof things might seem to change a little. Things may lookdifferentto you than they did before. But don’t let appearances fool you. There’s always only one reality.

At the time, Aomame had found this odd, but she had had no idea what he was trying to tell her, so she hadn’t given it much thought. She had been in too much of a hurry to puzzle over riddles. Thinking back on it now, though, his remarks had come out of nowhere, and they were truly strange. They could be taken as cautionary advice or an evocative message. What was he trying to convey to me?

And then there was the Janáček music.

How was I able to tell instantly that it was Janáček’s Sinfonietta?And how did I know it was composed in 1926? Janáček’s Sinfonietta is not such popular music that anyone can recognize it on hearing the first few bars. Nor have I ever been such a passionate fan of classical music. I can’t tell Haydn from Beethoven. Yet the moment it came flowing through the car radio, I knew what it was. Why was that, and why should it have given me such an intensely physical—and intensely personal—jolt?