The convenience store's fluorescent lights hummed at exactly 60 hertz. Syn knew because she couldn't stop her brain from calculating it, just like she couldn't stop noticing the security camera's refresh rate or the pattern in the cashier's breathing. *Seventeen breaths per minute. He's calm. Good. Less likely to notice me.* She pulled her hood further down, fingers twitching inside worn gloves as she reached for a protein bar. The wrapper crinkled, *Too loud, why is everything always too loud?...