Mira woke before the 05:40 southbound and lay still, listening. The rails sent their usual tremor through Building 7B, but under it—like a radio station bleeding between channels—was a thin fizzing, as if the city's wiring had learned to whisper. She pressed her palm to the floor again. The buzz tickled her skin and stopped the moment she noticed it. _Imagination_, she told herself, same spell as yesterday.
At breakfast her mother slid a chipped blue mug across the table. "You were restless," she said—not a question, a file-annotation. Mira shrugged. "Dreamed about pipes." Her mother's eyes softened. "Don't talk about pipes at Mentor Hall." The warning was affectionate and ironclad; Mira knew which received-first.
Junction 4 smelled of wet concrete. Overnight rain slicked the channel dividers, and workers laid temporary traction tape in chevrons. Mira stepped around them, counting pulses so she wouldn't have to think about the hum in her molars. Eli wasn't at his post, but he'd left a twist of paper tucked in the bead crate: a quick diagram of camera arcs and the words *12 seconds*. Mira memorized it, ate the paper corner (old habit, no evidence), and moved on.
Mentor Hall ran drills on "signal hygiene." Director Lian spoke while a map glowed behind her. "The tracks keep order. Static invites error. Error invites harm." The class repeated: _Static invites error._ Mira wrote it, then doodled a tiny lightning in the margin. Director Lian paused mid-aisle. Mira flattened her palm, covering the mark. Lian's gaze swept on, but Mira felt her ears go hot.
Practice was route-recitation, Sector 7 to Transfer K. They marched in step; Mira focused on the girl ahead, Nia Ren, Cycle-15 with a laundress mother and a habit of correcting teachers under her breath. Today Nia's collar tab was crooked, bar codes catching the light. Mira wanted to reach forward and straighten it—Nia would get flagged, and Mira would be named an accomplice. She kept her hands at her sides until her nails bit half-moons into her palms.
At transfer, a rail cart stalled with its doors open. Lian directed them around, calm as weather. Mira's boot landed near the gap. The cart's undercarriage gave a sub-audible whine—then every lamp in the corridor blinked once, twice, a lazy wave. A dozen students gasped. Mira went cold all over: she had felt that whine inside her sternum a second before the lights reacted.