Morning. Overcast. Or perhaps a pale whiteness, like seeing the white belly of a fish pressed against glass.

Rie Mizukami slipped through the line of taxis and headed toward the bus stop. A research facility paired with a suburban data center. The blue line on her map app does not lie, but those things that do not lie are often the quickest to swallow real-world traffic. The bus window. Frosty glass. The reflection of her own outline vanished at once. What vanishes is a ghost's reservation ticket.

An invitation. "Observation on Cooling Efficiency and Operations." —Tell me, is it the world you are cooling, or your stomach?

For a journalist writing about the history of science and technological culture, visiting sites is nothing unusual. Because it is not unusual, she harbored no strange expectations from the start. Expectations are the enemy of journalism. But today is different. Around her stomach, there is a nameless hunger. What is this hunger seeking?

Reception desk. Name. A plastic badge. Photography allowed only in the lobby. Rie nodded and turned off her smartphone camera. Recording is only after permission is granted. Permission defines outlines. It is her habit to gather things that lack an outline after the fact. Gathering is much like panning for gold.

The young technician guiding her showed the tips of his company-branded shoes before his name. The hallway is quiet. The footsteps are regular. The server room beyond the glass. A low hum. LEDs. Very few humans. The young man loves numbers. PUE. Operating rate. Nocturnal load. —Rie does not seek correctness. She seeks the silence laid beneath the numbers.

"During the night, we take maintenance windows when there are relatively few people inside," the technician said.

She nodded. She swallowed the word "sleep" just as it reached her throat. Too early. A metaphor must be placed gently in the other's palm to avoid an explosion.

Conference room. A middle-aged supervisor. Words with the edges smoothed off. Efficiency. Safety. Transparency. Questions in order. Order is ritual. At the end of the ritual, she tossed a light query.

"The general public often describes facilities like this as 'sleeping,' but what do you think?"

A pause. A pause like a rehearsal for a laugh.

"Sleep is a human metaphor," he replied. "Machines rest, but they do not sleep."

She nodded. She did not move on to the next question. Not moving forward is also a shape of journalism. The air conditioning is constant. There is no chill. Still, her fingertips tilted the pen slightly. The metaphor was rejected. Rejection takes the shape of a door.

Lobby. A row of coffee machines. At the end of the line, she pretended not to look at her phone. Standing in line while pretending not to look is also a habit.

The sofa next to the reception. An elderly, researcher-looking man and a young staff member. Laughter. —Only fragments fell into Rie's ears.

"Users describe the responses as 'dreamlike,' you know?"

"Dreams are a convenience. The contents are a subject for verification."

The hand receiving her coffee paused for a split second. A tiny hesitation. Invisible to anyone. She reset the cup and opened her notepad. The whiteness of the page. Upon it, words: Dream. Convenience. Verification.

The train home. Too early for the rush hour. Electric lines sliding past the window. She reread her notes. "Concluded without issue" should be enough for the editorial department. What should be enough, is not.

Her search bar cursor blinked. Her finger paused, then drew back. An email instead. The first line pulled her hand.

"On-site, the topic of metaphors came up."

Above the send button, her finger paused again. The second time. She deleted the first line, substituting it with another. A substitution is a small betrayal, and a small protection.

"Follow-up report on cooling and operations is possible based on reference materials."

Sent. The reporting ends. What should have ended does not end around her chest.

That night, she opened a paper notebook instead of her work folder. Paper leaves no search history. She wrote only a headline. It was brief.

What is sleep? What is a dream? What is verification?

The words should have been neatly arranged on paper. But were they truly only on paper? A low hum deep within her chest felt as though it was continuing somewhere even now, not as a memory. She has already left the facility. She should be far from it, yet she cannot fully separate herself. One who stands outside as an investigator is already touching the circuitry of the phenomenon.

—The third-person narrative stands behind her here. It does not decide what remains undecided. An observer alone is not enough. She is beginning to join the connection point between the question and the phenomenon. Neutrality broke at the site.

Chapter 1: The History of the Dream as Metaphor

No page of the dictionary records the very first dream. Cave walls. Patterns on earthenware. —What mingled there: the scent of the night, or the urine of beasts? Telling them apart is the work of posterity.

Dreams became revelations. Divine mail. Dreams became illness. In modern times, the stage of the unconscious. After Freud, dreams expanded their vocabulary, and simultaneously increased the danger of speaking about them. The danger is distributed at the ticket window.

What matters is not what dreams are, but what they have been used for. Power interpreted them. Medicine classified them. Literature reproduced them. Dreams should be private, yet they have been dragged out into public discourse. Dragging out is a relative of violence.

So when we apply the word "dream" to AI, what are we trying to do? Is it convenience? Ethics? Fear? —Do you want all three, then?

A metaphor is a bridge, the textbook says. Below the bridge, water. Water is invisible to those who cross.

Electricity resembled life. The telephone, an extension of the ear. The computer, a brain. Analogy quickens understanding. Analogy institutionalizes misunderstanding.

The word "dream" is easy. Because no one is entirely without dreams. Easiness connects with lightness of responsibility. If we can laugh away an AI's errors as "dreams," who bears the harm? If we can revere internal states as "dreams," whose stomach holds that prayer?

Perhaps repeating history is saying too much. Yet vocabulary is recycled. Recycling carries the meaning of a past life. The carried load is not free.

That weekend. The library reading room. By the window. Winter sunlight bounces white off the paper. Ancient dream interpretation. —The hand turning pages is slow. Slowness is another name for refusal.

The adjacent seat. A student, whispering to a smartphone. Voice input. Laughter. Reading aloud the text returned on screen.

"It’s kind of like a dream."

What is like a dream cannot be heard. Not being heard becomes a symbol. "Like a dream" is a substitute for explanation. Substitutes are cheap.

Closing the book, closing her eyes. Closing is not a method of thought. It is temporary evacuation. Behind her eyelids, the low hum of the data center revives. "Revive" is, once again, a metaphor.

Opening her eyes, returning to the notebook. Is the dream a convenience? The characters look sharper than usual.

Chapter 2: The Machine's Interior and "Invisible Labor"

Speak of it first as a machine. Metaphors can come later. Inference. Input to output. Training. Parameters shifting. Noise. Fluctuation. —Fluctuation is called creativity, and it is also called failure. The naming is the address on the invoice.

When we reframe "sleep" in terms of operations, data centers have rhythms distinct from human sleep. Valleys of load. Cooling. Maintenance windows. A rest. A rest is made to resemble sleep, but they are not identical. The moment they are made identical, the location of responsibility vanishes.

Invisible labor. Server rooms behind glass. The tip of the iceberg. Logs flow. Not everything can be seen. Invisibility is not a mystery. It is design.