Chapter 32

The next morning I woke with an unexpectedly simple, sober, and cleanly angry thought.

If the solution to a problem seems impossible — it means I stated the terms of the problem wrong to begin with.

This axiom had been taught to me long ago, back in my first year, by an elderly professor of mathematical modelling. He liked to repeat: "There is no magic in our universe, Lawson. There is only incorrect or incomplete input data. If your system behaves like a poltergeist — you've simply forgotten to account for a hidden variable."

I lay on my back, staring at the bedroom ceiling with its fine web of cracks, until it finally landed on me. For all these past weeks I had been making a fundamental methodological error. I had stubbornly been trying to answer the question: "Who exactly is speaking to me through a switched-off headset?" When, as an engineer, I should have been asking something entirely different.

By what physical means am I hearing anything at all?

These were fundamentally different questions. The first led into a dead end of paranoia. The second — brought me back onto the field of classical physics.

I got up, washed, put the kettle on. Then I called Helen.

An hour later she was sitting across from me at the kitchen table, cupping a mug of tea in her hands. In the centre of the table, on a white napkin, lay the bone-conduction headset.

That one. My constant companion of the last months.

I held down the power button, waited for the indicator to go out completely, and waited a couple of minutes more. The device was dead — no pairing with the phone, no network connection. Then I took a scalpel and a thin plastic pick for opening gadgets.

"Are you sure you want to do this right now?" Helen asked quietly.

"Absolutely not sure," I replied, working the edge of the pick into the tight seam of matte plastic. "But I'm out of other options."

The casing resisted. Then it gave a dry, short click and opened into two even halves, baring its insides.

At first glance — all standard. A factory printed circuit board of green fibreglass, microscopic ribbon cables, a tiny Bluetooth-module chip, an antenna, a flat lithium-polymer battery. A typical assembly-line build.

I was about to let out a disappointed breath when my eye snagged on the area near the base of the arm — where it ran to the vibration transducer. In the narrow technological gap, a barely visible bead of clear epoxy compound gleamed. Too neat to be an accidental runoff. Too alien for robotic manufacture.

Factory lines don't do that. This was manual, jeweller's-grade rework on a finished product.

I carefully lifted the bead with the tip of the scalpel. The compound peeled away.

Beneath it was an additional component — deeply integrated into the circuit, microscopic, a little smaller than the nail on my little finger. On the tiny flat disc, laser-etched markings were barely legible.

Six milliamp-hours. An ultra-miniature solid-state battery. An autonomous, fully isolated backup power source, soldered in around the main controller.

I turned the silvery dot over in my palm for a long time. Fragments of the mosaic were beginning to snap into place — not all of them, but enough to break the mystical spell.

"Helen," I said. "Remember that first day at your flat? When Clara spoke to me in an empty room?"

"Of course. You looked like you'd lost your mind."

"But you didn't hear a sound. Even standing right next to me. Why?"

She frowned. I picked the plastic arm up off the table and pointed at the elongated rubberized pad on its end:

"When it's worn, it doesn't touch the outer ear but presses directly against the temporal bone." I tapped a nail on the plastic. "The vibration transducer converts the electrical signal into acoustic oscillations that travel through the skull bones straight into the inner ear. Bypassing the eardrum. The sound physically did not exist in the space of the room, Helen. It was broadcast exclusively into my head."

She slowly leaned back against the chair. Her face went pale.

"So... if the sound didn't travel through the air, and the device was switched off..."

"So if somewhere at very short range there's a powerful directional transmitter in a closed frequency band, this headset doesn't need main power. It doesn't need Bluetooth switched on and it doesn't need a cellular network. The energy of this hidden micro-battery and an induced electromagnetic field is enough to activate the piezo element in passive mode."

I fell silent, reconstructing in my mind the engineering topology of this network.

Low power. Ultra-short range. A directional beam. No satellites, no internet, and none of the London towers Clara had complained about so neatly last night. Pure, local short-range radio.

"That's why," Helen said in a barely audible whisper, "that's why I couldn't record anything on a dictaphone."

"Exactly. There were no sound waves around me. There was only a directional radio signal, picked up by the modified arm."

We both fell silent at the same moment — and took the next inevitable logical step the schematic dictated.

If the system critically needed a local short-range transmitter... then that transmitter had to have been physically near me. Always. At a distance of no more than a few dozen metres. Throughout all these weeks.

I stood up sharply and went to the window.

Third floor. A quiet London courtyard well. A small tarmac car park, a line of postboxes by the gate, a couple of parked saloons, refuse bins against the wall. The most ordinary urban scene. Which is exactly why I had never once let my eye catch on anything.

I went back to the table, picked up the black notebook, and began quickly turning the pages. Every recorded meeting of mine. Every sudden cut-in of Clara onto the air. Every long night conversation. Out of systems habit I had always noted the exact date and place in the margins.

Five minutes later, on a blank sheet in front of us, was a short list:

My flat in Camden.

The office in Bloomsbury.

The staff car park by the ministry.

The café in Victoria.

The backstreets of Camden.

The abandoned Harris & Croft branch.

I turned the sheet toward Helen:

"What do these points have in common from the standpoint of urban infrastructure? Which variable is present everywhere?"

She stared at the list for a long time, unblinking. Then her eyes widened.

"Cars, Michael. Surface car parks. In every one of these places you were either behind the wheel yourself or in direct line of sight of a roadway or a parking area."

I smiled — for the first time in a very long while. Not with relief. With the cold, predatory engineer's satisfaction of a man who has finally located a specific fault in someone else's architecture.

"Bang on. A closed-loop transmitter doesn't have to be a stationary tower. It's hundreds of times simpler and more mobile to carry it after me on wheels. To keep it in the boot of an escort car that always parks within a thirty-metre radius."

And it was at that exact moment that the air in the room seemed to freeze instantly.

The headset — dismantled, its batteries desoldered, lying on the white napkin in two halves — gave a barely audible dry click.

Helen and I turned our heads at the same time.

The main battery was fully desoldered. The microscopic silvery backup-power battery lay separately, gripped in the jaws of steel tweezers. There was not a single energy source on the board.

And yet, deep under the semi-transparent plastic of the opened casing, the tiny red status LED blinked briefly for a fraction of a second. Once. As if it had registered a spike in an external electromagnetic field.

And immediately went dark.

Helen and I exchanged glances in absolute silence.

"That's physically impossible, Michael." Her voice broke. "There's no power. None at all."

I slowly shook my head:

"No, Helen. It's actually possible. It was impossible before, when I believed in cellular connections and standard wireless protocols. Now it just means there's a passive circuit built into this arm — something like a backscatter RFID tag. It harvests parasitic radiation energy straight from the air, if an external transmitter somewhere nearby has just gone to full power."

Helen said nothing. She looked at the LED that had blinked with the expression of someone who has just been shown a magic trick and simultaneously had it explained to them — and the explanation made things not easier but more frightening.

Because a trick with a known mechanism meant one thing: someone right now, this very second, was sitting somewhere within a thirty-metre radius, listening to our conversation.

When Helen had left, I sat alone for a long time in the darkening kitchen.

In front of me on the table, as on a forensic examiner's dissection bench, lay the whole dissected nightmare of the past weeks. The plastic halves of the casing. The board with its traces. The desoldered batteries. The scalpel and tweezers.

Mechanically, to keep my hands busy, I took a blank sheet and began sketching a structural block diagram of the device — as I'd done hundreds of times in my working life. Power block. Receiver circuit. Frequency amplifier. Piezoelectric vibration transducer. Connection arrows, logic bridges, incoming and outgoing data flows.

At some point the hand with the pencil froze of its own accord in the centre of the sheet.

There, in the very heart of the control block, purely on autopilot, without thinking, I had written the familiar name.

Clara.

I looked at those five letters for a few seconds. Then slowly, bearing down hard, I struck them out with three thick lines. And directly above them, in a neat, cold hand, I wrote another word.

Interface.

The difference between these two concepts was conceptual. And it frightened me now far more than all the mysticism of the first days. Because a living person at the other end of the line can sympathize, be ironic, make mistakes.

An interface, though, is only a gateway. A technological intermediary that lets you hear, through the bone of your skull, whoever is sitting on the other side of a closed console.

Whoever is right now coordinating your every step.

I folded the sheet in four and put it away in the notebook — between page thirty-one and page thirty-three. Where page thirty-two should have been.

It felt like the right place.