The evening harbour lights twinkled as fourteen-year-old Nina slid her backpack under her desk. After a day at school, all she wanted was silence and a breath of iodine from the bay. The silence didn't come as the walls of the block hummed an unfamiliar melody, raw and warm. Nina took off her headphones, although the music was not coming from any device. The melody seemed to match her thoughts, as if it were a hidden mirror. She touched the windowsill, and the glass vibrated as she said her name in a half-whisper. She tried again, lengthening the voice, and the metal blinds trembled like strings. Her heart pounded, but curiosity was stronger than the fear of the strange silence. She tapped a rhythm on the countertop with her fingers, and two short taps answered from the radiator. It's not an echo, she thought, it's someone teaching me the alphabet of sounds. A minute later, the whole stairwell went out, as if someone had unplugged the night. The harbour sirens drew one long tone and froze at the edge of the sound. In the darkness she heard a sequence of taps, precise as a metronome and impatient. The rhythm arranged the words in Nina's head, although she had never learned Morse. Come to the roof, now, alone, for time is getting tight, sounded in her temples. She picked up her torch, phone and jacket, and the keys rang like a sharp rain. The stairs climbed high, the railing was cool and the air smelled of copper. On the roof the wind always won its own, but today it was silent at her beck and call. At the foot of the mast hung a drone, smooth as a fish, with a blue wave mark. A loudspeaker crackled until it folded into a clear whisper: Nina Struna, the test begins now. The slabs trembled beneath her feet, and a shape emerged from the darkness that cast no shadow. She heard her voice, as if speaking from the future: if you don't play, the city will fall silent. The drone unfurled a thin net of waves that danced over the city like transparent threads. The shape pointed to the mast, and simple, alien notes appeared in Nina's head. Start with a, stop the clocks at three, let people's breath pass, he whispered without a mouth. Nina took in air deeply and sang softly until the steel of the mast buckled. The harbour lights responded with a wave, the trams rang and the city bent like a drum. Then, behind her back, someone turned on a second tone, identical but a step earlier. The roof leapt up, the drone flicked, and the shadowless shape turned abruptly towards Nina. A counter melody came from the stairwell, and each bar of it sounded like a blade. If you answer now, the whisper warned, someone else will answer for you faster. Nina tightened her fingers on the banister and heard her name crack in half.