Lena was fourteen years old and hearing things that others didn't catch. On the roof of the house above the old shipyard she was assembling aerials from parts of school drones. Her dad repaired detectors on a radio telescope that looked through the clouds. On warm nights the metal towers carried the sky like scaffolding for the planets. The city smelled of salt, ozone and grease, and the horizon vibrated with turbines. From above, the orbital ring could be seen, a thin line cutting through the purple twilight. That night her receiver buzzed, even though the band was officially closed. A string of characters and a drawing of a circle cut by a spiral flashed on the screen. Then a name appeared, her school nickname, and the date of tomorrow noon. Lena called Maks, who believed only in numbers and good screws. He arrived in a reflective jacket, carrying a meter and an algae-flavoured bar. They locked the door with a bolt, then turned on the recording and froze at the speakers. With a hum, a metallic voice whispered: "Lena, don't turn on the lights at 12:07". The code annotated the co-ordinates and tag: lock number three, EON dredge, no-go zone. The file identified the sender as a nanosat, launched last year by the school. Only that the time signature matched tomorrow, as if it was waiting in a loop. Maks swallowed his saliva and asked if this was a joke from the physics master. Lena felt the table tremble under her fingers, as if a wave had passed through the beams. They went by the canal, where dulled stars reflected in the oily sheet. Drone patrols circled high, but the sluice valley whispered only of water and rust. On the concrete wall they found a spiral sign, identical to the transmission. Underneath it was a panel with three LEDs and a slot for an old card. Maks took out his school ID, although his hands were like sugar and glass. As he slid the card in, the counter flashed, counting backwards from silence: ten, nine, eight.... A chill rose from the sewer, as if someone had opened the fridge underwater. Lena glanced at her watch; the hour indicated twelve six and fifty. Then a second voice, much closer and echo-shattered, beeped from the loudspeaker. "If you can hear it now, don't look at the light," he said breathlessly. The lights flickered, a pale halo glowed over the canal, and the counter whispered: seven, six, five...