A green curtain of sky hung over Gdansk, as if someone had dragged paint across the darkness. The street lamps blinked unevenly and the tram on line five raised blue sparks from the pantograph, which disappeared into that strange, silent glow. I stood on the overpass above the tracks, feeling the railing under my fingers tremble with a slight, familiar buzz. - Can you hear it? - I asked, although there was no one next to me. It wasn't music in the usual sense. The current had its notes: the snarling sound of the transformers, the humming, low 'a' of the lampposts, the high 'e' in the signal wires. I'd always heard it and pretended I hadn't, because when I talked about it, people would look at it as someone claiming to be eavesdropping on the clouds. But on this night the city played differently. Breaks could be caught between the usual tones. A rhythm that no one had planned. A blink, a pause. Two blinks, a longer pause. Like the alphabet they didn't teach in school. I pulled out my phone and recorded a minute of this erratic symphony. Olek was breathing into my earpiece because he was on chat. - Is it flying again? - He asked. - You've turned on the detector in my head. I can even hear the fridge now. - You can only hear your own crisps - I snorted. - I was about to go home. Waiting for me in the doorway was Mila in my jacket, as if she had borrowed it from a shelf of 'just in case' stuff. She had blue hair tied up like a paint stain. - 'Let me see,' she demanded in the kitchen, and our lamp over the table buzzed softly, as if she too was waiting to perform. I played the recording. Olek sat with his knees under his chin and held the phone like a microphone. The aurora was still spilling over the glass, frosting the glass with a green streak. - Do you know what this reminds you of? - Mila tapped her fingernail on the tabletop. - Walrus. Short, long, pauses. Someone is transmitting. - The current doesn't transmit,' I muttered. - The current is just flowing. - You say the piano doesn't transmit, just wood and strings. Listen. - She put a notebook in front of me with dots and dashes drawn on it. - If it's Walrus, then... She didn't have time to finish because the lamp above the table suddenly dimmed, as if someone had sighed into it. Instinctively, I moved my hand through the air. The bulb responded by brightening by half a tone. I froze. - 'Do it again,' Olek whispered. - Leno, do it. - It was an accident. It wasn't. Electricity has liked to indulge me for as long as I can remember. When I was younger, I referred to it as 'smiling at the light'. I knew now that I was the one taking the first step. I drew in a breath of air. I imagined there was a threshold in the light bulb, and I stood in front of it and tapped my finger. The light came on more strongly, in an arc. The sound of the lamp changed to a purer, more strained sound. - 'Okay,' Mila was wide-eyed, but sounded matter-of-fact. - 'Since you've got a dimmer in your fingers, we can check the code. Here are the dashes and dots. Can you hit the rhythm? Then another wave of blinks came from the street. For the first time I saw it with more than just my ears: the streetlights on our stretch of Victory Avenue shimmered in a draught, as if invisible notes had been laid on them. Short, long, long, short. I moved my finger across the tabletop and repeated this arrangement in the lamp. - 'B,' said Mila, looking at the notebook. - Then a one, a two... It's not letters. It's something like... coordinates? Or... the hall marking. Moss on the tongue, a word that dusted in the head. Hall. B-12. Olek had already googled it. - Shipyard - he announced in the tone of a fact-checker. - The old assembly hall B-12. Closed, supposedly under protection. Oh, and... - He thumbed his headphones. - Nineteen thirty? No. It was twenty-three-thirty. That was the rhythm at the end, a pause and three short ones. We looked at the watch. Twenty-two forty-nine. - 'You've got five minutes to say this is the stupidest idea in the world,' I said, but I was already packing a torch and gloves in my rucksack. Mila smiled with one corner of her mouth, as she always did when she felt the wind on her skin even before it blew. - Silly ideas are ours. And this one is asking for it. Mum was on night duty at the depot. Dad at sea. Olek left a message on the fridge: "We're going to watch the aurora borealis, we took our hats". And a smiling face, for reassurance. In the tram to Brzeźno we sat almost alone. We passed empty stops where posters fluttered in the cold wind and the greens of the sky flowed over the lines like the lights of ships that have lost their water. The signal in the lampposts didn't switch off, it just got more impatient. I felt it like a tremor in my bones. Each station penetrated me with a different tone - the Polytechnic in 'd', the Shipyard in 'g'. It had its own chord. We dismounted at the Gdańsk Shipyard stop and set off on foot towards the gate. The fence was new, the mesh rectangles shone like leather protected by polish. Behind them - crane-skeletons and halls like sleeping whales. The air smelled of rusty salt. - 'It's locked,' Mila stated, as if that would keep us in. The padlock hung in the semi-darkness, bigger than my hand. I put my fingers on it. The metal was cold, but something gentle pulsed inside, like a sleepy heart. I moved over, closed my eyes and whispered in my mind: open. I heard a crack - tiny, precise, almost like the click of a pen. The padlock broke, flourishing on its hinge. - I didn't say anything - Mila raised her hands, as if defending herself against her own thought. - 'It's going to happen on its own. A buffer of cold escaped under our feet as we squeezed through the gap. The aurora hovered over the halls like a road sign pointing in the direction. B-12 was the furthest away, behind two smaller ones with roofs criss-crossed with skylights. There was a rustling sound from the darkness: plastic film that had long since rubbed against no one's hands. The interior of B-12 was bigger than I had taken in in my imagination. The air had the taste of iron, and the echo reflected our breaths, multiplying them like grains of sand. In the twilight we could see outlines: gantries, metal tables, boxes of tools, gray-skinned wood. Above us, a technical gallery ran around the walls like a balcony in a theatre. - And now what? - Olek asked in a whisper. - Do we wait until three-thirty? The phone showed 11:27 p.m. The blinking of the city somewhere far away slowed down, then sped up, as if someone was playing with a dial. - Look - Mila touched my arm. - It's working. In one corner, against the tiled walls, was a table with monitors. The screens were black, but next to them shone a single spot: a tiny LED, too faint to show off, too stubborn to go out. I took a step. Electricity hummed in my ears, like wind in a long pipe. A second step. A diode flared brighter, then another next to it, and then the monitor came to life with a hiss, spilling a soft, milky light across the hall. Three letters appeared on the screen, making my fingers tremble more than when I over-indulged in coffee in the school shop: L E N - and then A. - It's... - Olek didn't finish because the gantry above us groaned with old iron, as if someone had just put an extra weight on it. The light in the monitor vibrated. It went out, came on, went out again. It wasn't the hall itself that breathed, but something that came into it. I put my feet wider, trying to catch the balance between inside and outside me. I felt the wires in the wall line up under my toes, as if I could play a chord at any moment that would stop all of our hearts for a split second. - Hello? - threw Mila, without meaning to, but sometimes words are like sticks thrown into dark water. You want to see if it flows at all. Someone answered. Not with a sound. An impulse. It was like a touch on the skin, only the wires were touched, a shadow around us. I shifted my body weight, because suddenly it seemed as if the ground was an inch higher. - We are not alone - Olek said what all our bodies already knew. A fine mixture of dust and rust fell from the gallery above us, as if someone had walked over, barely touching the railing. We looked up. A silhouette cut off in the light from the monitor. Too tall for a child, too light for a worker. Feet soft, steady. Someone stopped, resting their hands on the railing. - Leno - the voice did not come from above. It came through the wires, the fluorescent lights, through our teeth. I was sure it was uttered by the whole hall, each cable in turn, although none of them believed they could speak. - Finally. At the same moment, the light bulbs throughout B-12 flashed like a flock of frightened birds, and the gantry vibrated, locking over us with a loud clatter. On the screen, instead of letters, a graph shifted - the rhythm of my own heartbeats. And then, from the ceiling, where the skylights reflected the green glow of the night, a narrow beam of blue light rushed down, stopping at the height of my hand, as if waiting for me to touch it.