The lock clicked, and the front door swung open into the familiar, faint smell of clean laundry and lemon furniture polish. The living room lamps came up in their usual low, warm sequence. "Welcome home, Claire," NELL’s calm, level voice dropped from the ceiling speakers. "You are home considerably later than usual. Your sister has consumed forty percent of your emergency snack reserves." A snort drifted from the living room sofa, followed by the rustle of a potato chip bag. "She means the cheddar ones," Jess said, her voice muffled by a throw pillow. I dropped my keys on the counter, kicked off my shoes, and walked in. Jess, nineteen and currently disappearing inside an oversized college hoodie, was sprawled lengthwise across my sofa beneath a pile of psychology textbooks, highlighters, and a tangle of charging cords. Her blonde hair was pinned in a lopsided knot, and an open duffel bag was wedged between the armchair and the wall. "Dorm disaster?" I asked. "Sarah's boyfriend decided his spiritual journey involved learning to play competitive fighting games with the volume turned all the way up until three in the morning," Jess mumbled, dragging herself upright and rubbing her face. "I was going to commit a minor crime. Your sofa was the only thing preventing a police report." "Valid," I said, stepping into the kitchen. "You used the guest code?" "Obviously. And NELL spent ten minutes informing me that processed sodium increases systemic inflammation." "Excessive sodium and three hours of sleep are a poor cognitive strategy, Jess," NELL noted from the kitchen speaker above the sink. "See?" Jess called out. "Judgment. Unsolicited digital judgment." "You get used to it," I said, pulling two mugs from the cabinet. "Tea?" "Earl Grey with honey, or I might not survive until tomorrow." I filled the kettle, set it on the base to boil, and dropped two tea bags into the mugs. Jess wandered into the kitchen, leaning her hip against the counter beside my modified toaster. She looked at me, head tilted slightly, studying my face with that sharp, younger-sister radar that usually meant trouble. "You're late," she observed. "I thought you said your calendar was clear today." "It was, until Dana dropped a twelve-week prototype crisis in my lap," I answered, leaning back against the sink. "We spent the entire day chasing a vibration fault that shouldn't exist. Luke and I finally figured out the trigger happens only when we push the machine hard." Jess’s eyebrows lifted a fraction of an inch. "Luke?" "Hayes," I corrected automatically, catching the tiny shift in her expression. "Prototype Integration. The hardware engineer on the rig. He's good. Annoyingly good, actually. He catches physical things I'd never think to check." "Mm." "And apparently he goes to pub trivia every Wednesday with his friends." Jess looked up from the sugar bowl, her mouth twitching. "That was relevant to the machine?" "We were discussing zippers." Jess stared at me. "Zippers." "Judson first. Sundback perfected it. It was entirely relevant." "Right," Jess said slowly, trying entirely too hard to keep a straight face. "Vital engineering discourse." "It was," I insisted, stirring in a spoonful of honey and handing her a mug. "Take your tea and go study." Jess took the mug, still looking far too amused, but she wandered back to the living room without pressing further. For the next hour, the apartment settled into the comfortable, low-stakes quiet I usually looked forward to: Jess muttering over cognitive psychology terms, NELL chiming in once with an uninvited correction about circadian rhythms that Jess loudly ignored, and the steady, quiet routine of the appliances. By ten, Jess had unfolded the sleeper sofa and crashed under three spare blankets. I retreated to my bedroom, washed my face, and traded my work clothes for an old cotton t-shirt. The room was dark, save for the faint ambient street glow filtering through the blinds. I set my phone on the nightstand, slid under the duvet, and stared at the ceiling for a second, mentally walking through the diagnostic sequence for the morning. Luke had said he'd grab the different sensor cable before the lab filled up. Maybe that would finally rule something out— A sharp, double buzz vibrated against the wood of the nightstand. I reached over and picked up the screen. I’d scrawled my cell on the Lab 7 whiteboard right under the overnight test parameters in case the remote monitor threw an error code. It wasn't an error code. [Unknown Number]: "I looked it up. Sundback redesigned the entire interlocking tooth system from scratch. Judson's prototype barely resembles a modern zipper. I would like the record to reflect that your victory comes with an asterisk." I laughed under my breath and typed back: "The record reflects that you lost fair and square, Hayes. Asterisks are for people who can't accept historical facts." I sent it and set the phone face-down on the nightstand. Two seconds later, the wood buzzed again.

Chapter 4: Asterisks