Tamsin tightened her boot strap, clicked the harness twice as if the metal agreed to the ritual, and let the city settle under her like a sleepwalking beast. Streetlight hums threaded through the air; not the random, bureaucratic buzz of cheap fluorescents but a low, obsessive murmur that older signal technicians swore had taste. It liked minor keys and the smell of frying dough. Tonight, the hum was a little off—a hesitant hiccup halfway through its phrase—and Tamsin worked by ear. She’d taught herself to hear the drum of a timing wheel the way other people learned a lullaby. Her hands knew which bolt asked to be kissed and which wire needed a reprimand with a pliers’ jaw.
She mounted the mast like someone taking up a small argument with gravity. The harness sang against the metal, rope whispering through her gloves; she threaded a figure-eight knot so neat the rope might have been put on display in a municipal museum dedicated to things people used but did not appreciate. The city from this height looked industrious: rooftop tea stalls with paper lanterns bobbed under awnings, a fleet of battered delivery bikes that smelled perpetually of citrus and engine grease, and the occasional string of laundry that flapped like cheap banners. None of that mattered except as background noise for the true business of the night—keeping lights honest.
She pried the housing lid with the flat edge of her hand and the clack of a well-worn screwdriver. Inside, the timing drum rotated with the patient authority of a man who had no more places to be. Tamsin listened, leaned close, and frowned. The drum missed a tooth; the hum took on a little stutter, like someone tripping over a favorite joke. It was tiny, the sort of micro-failure that would be a footnote in a morning report and a catastrophe at midnight market hour. She ran a gloved finger along the drum’s spokes, feeling the vibration travel up through her bones the way someone reads Braille.
A busker’s voice floated up from two blocks away, raw and bright, threading a melody into the street. Tamsin smirked. Music could be an accomplice or a witness. She hooked a wire, tightened a contact, and murmured at the conduit as if coaxing a cat. “Behave,” she told it, more to postpone bad things than because it understood.