Nela stood on the roof of the school, watching the trams glide by below. The cold wind carried the smell of the sea, and the cables sang quietly in the railing structure. She was the only one who could hear this singing, without headphones or antennae. For a year she had been able to read the current as others read the map of the school corridor. Mum worked on the nets, but she did not believe Nela's stories. That's why Nela kept quiet, choosing the roof and the quiet while the others played basketball. She soldered a micro-receiver in her dad's old headphones to catch the pulses from the city. Today the signal was different, stretched like a rubber band, jumping between the lampposts on the pitch. - Hello, Nela? - sounded in her head, although no one was standing near the entrance. She froze, because by now the current didn't know other people's names. Once signals were like ants, harmless, busy with their secret paths. This one had the tone of a human, trembling and desperate, asking for quick understanding. In the valley of the streets, the neon lights dimmed and the tram braked as if someone had cut the voltage. A boy in a yellow jacket climbed from the opposite direction, carrying a skateboard under his arm. He looked at Nela's headphones and raised his eyebrows as if he recognised the tool. - Can you hear it too? - He asked, quietly but confidently, pointing to the sky above the art room. A triangular patch of darkness hung over the school, flashing like a broken phone screen. On the pitch, the pupils froze and the ball rolled, uncertainly, along the line. - 'It hurts,' said the same voice in the cables, 'someone is cutting the net like scissors, leaving sharp shreds. - I'm Oskar - the boy added in a whisper - don't turn the phone on, it attracts something like a magnet. Nela raised her hand and touched the railing, asking the electricity to respond. The metal whined and a white tremor flew across the ground, drawing lines to the pitch. The stain contracted and sent a thin, sharp streak downwards. An usher's shout came from below, but the echo was sucked up by the black stain. The air smelled of ozone and metals, like the welding room at tech. The lantern bent like a thin can, as if it were made of paper. - 'She's coming for you,' said a voice, and all the bells in the cables chimed at once. Oskar grabbed Neli's wrist and pointed to the hatch to the ventilation chamber. - 'Let's hide in there, or try to block it, quick, decide now.