Chapter 72: Morning Mist and Luggage

The rain stopped at three in the morning. When Lin Chen woke up, the sky outside the window was that gray-white color soaked through with moisture. The dormitory building was very quiet; only the intermittent drip of water came from the washroom at the end of the corridor. He did not get up immediately. Instead, he first stretched his left foot out from under the blanket. The edge of the gauze had already dried and stiffened, and the seepage had stopped, but the skin around the wound was an unhealthy dark red, and half a degree warmer to the touch than the rest. He pressed it lightly. There was no sharp pain, only a dull swelling ache. The three-day dressing change was due. He sat up slowly, careful not to pull at the fascia around his ankle. From the drawer he took out iodine, cotton swabs, and spare gauze, unscrewed the bottle, and the pungent medicinal smell spread through the cramped space. Lowering his head, he used the swab to wipe from the center of the wound outward in a spiral, avoiding the scabbed areas, his movements light and steady. When he was done, he sprinkled on a thin layer of drying powder, covered it with fresh gauze, and fixed it in place with tape. The tightness was just right. His toes could still move slightly, and it would not affect his gait. By the time he finished, it was already 7:15.

The campus clinic had not opened yet, so he waited on the bench in the corridor until 7:30. The doctor on duty was a middle-aged man wearing reading glasses. He looked at Lin Chen’s foot, asked no unnecessary questions, and simply prescribed two packets of medical drying agent and a new bottle of iodine. After paying, Lin Chen had 6.8 yuan left. When he walked out of the clinic, the mist still had not lifted. Beads of water hung from the camphor leaves by the edge of the athletic field, and whenever the wind stirred them, they struck the blue bricks with a fine, broken patter. He detoured to the bus stop and checked the early route timetable. The original first bus at 6:20 had been temporarily rerouted along the old national highway because last night’s torrential rain had washed out a section of roadbed in the western suburbs. Departure had been pushed back to 6:40, but the arrival time remained unchanged. That meant his time on the bus would be shorter, but the walking segment after the transfer would gain an extra stretch of gravel slope. He took out his notebook, flipped to a blank page, and redrew the route map in pencil. The gravel slope was steep, slick with wet moss, and his left foot could not risk taking full weight on a slip. He would have to shift to the right side at the base of the slope, drive forward with his right foot, and let the left foot only touch lightly. His stride length would have to shrink from thirty centimeters to twenty-five. Three minutes of time margin would be eaten away. After finishing the calculation, he closed the notebook. He could manage it.

At exactly eight, he pushed open the door to Laboratory No. 3. The air held that familiar mixed smell of rosin, old circuit boards, and dust. Old Li was not there; only two third-year students were sorting cables. Lin Chen went straight to the workbench by the window. The HP8591E spectrum analyzer stood there silently, its power indicator dark. He reached out and touched the side of the chassis. Ice-cold. Cold start. He plugged it in and pressed the switch. The fan began its low hum, the screen lit with its self-check program, and green characters scrolled line by line. He kept his eyes on the stopwatch. The warm-up indicator did not change from red to green until the fourteenth minute. The noise floor curve climbed slowly across the screen and finally stabilized near -115 dBm. Exactly as he had calculated. But the problem was that the exam rules allowed only twenty minutes of practical preparation time. If the equipment was cold when he entered the room, the first five minutes of data would all be drift values. He had to finish powering on, warming up, calibrating, wiring, and testing within those twenty minutes. There was not enough time.

He looked around, and his gaze fell on the power distribution box in the corner. The power strip had an independent switch, but the keyhole was sealed over with tape, and beside it was a printed notice: “Operation strictly prohibited for anyone other than proctors.” The invigilators would never allow the power to be turned on in advance. He returned to the bench and took the homemade attenuator out of his canvas bag. Its metal casing was slightly cool, and the threads on the BNC connector bit together tightly. He connected the test lead, leaving the other end unloaded. The screen showed the input impedance was matched normally. He closed his eyes and ran through the procedure in his mind. Enter the room. Power on. Do not connect the signal source. Run one scan of the noise floor first. Use those five minutes to substitute the temperature drift coefficient into the correction formula. Once warm-up was complete, go straight to signal. Manual attenuation: ten dB. Reading. Compensation. Output. Not one step could go wrong. If one step went wrong, the data chain would break. He opened his eyes, put the attenuator back into its insulated case, and pulled the zipper shut. There was no shortcut. He could only compress the margin for error to its limit.

At 9:30, he returned to the dormitory and began the final inventory. The canvas bag lay open on the bed. In the insulated case: the attenuator, multimeter, graph paper, waterproof plastic bag, gray shirt, cardboard shoe insole, drying agent, iodine, two cold steamed buns, one packet of pickled mustard greens, and a military canteen filled with water. He checked them off against the list one by one in red pen. There was nothing extra, and nothing missing. He had 6.8 yuan left. The eighteen-yuan bus ticket had already been bought and was tucked into the pocket closest to his body. Emergency funds: zero. He did not care. Survival required no redundancy, only precision. He picked up the letter from his mother. The paper had already gone a little soft, and the edges were worn fuzzy. He did not unfold it again. He only ran his fingers once over the crease, then slipped it into the innermost compartment of the canvas bag, right beside Principles of Measuring Instruments. It was very light, but enough to hold down the center of gravity.

At noon, he ate the last steamed bun. At two in the afternoon, he changed into the gray shirt and tightened his shoelaces. His left foot slid into the shoe, the cardboard spreading the pressure under the ball of the foot. He stood and took two steps. Twenty-five centimeters. Avoid the puddles. His gait was steady. He shouldered the canvas bag, the strap biting into his collarbone. The weight was evenly distributed. When he reached the ground floor of the dormitory, he saw a new supplementary notice posted on the bulletin board. The paper had clearly been soaked by rain; its edges curled, barely held in place with transparent tape. He leaned in to read it. It was a temporary adjustment from the provincial electronics competition committee: because of maintenance on the exam site’s power grid, a backup diesel generator would be used during the practical session in Laboratory No. 3. Voltage fluctuation range: ±5%. All precision instruments would require an additional “power ripple calibration” step. Estimated time: four minutes.

Lin Chen stared at that line. Four minutes. Out of twenty minutes of preparation, a full fifth had been carved away.

Cold-start warm-up: fifteen minutes. Noise floor calibration: three minutes. Power ripple calibration: four minutes. Wiring test: two minutes. Twenty-four minutes in total. Four minutes over the limit.

He did not frown, nor did he sigh. He only took a pen from his pocket and quickly wrote out a new timeline in the blank space of his notebook. Merge the noise floor scan with the power ripple calibration. Use the first seven minutes of the warm-up period to record the voltage fluctuation curve at the same time. Replace hardware calibration with software compensation. The amount of manual calculation would increase, but the time could be clawed back. The risk was that if the generator caused a sudden voltage drop at startup, the spectrum analyzer might reboot. Before powering on, he would have to factor in the discharge time of the power filter capacitor. Check the attenuator’s input impedance one more time. Multiply the coefficient in the correction formula once more. He calculated very slowly, the pen tip making a dense rustling sound across the paper. Outside the window, the cloud cover split open along one seam, and sunlight cut down at an angle onto the wet concrete. The wind carried the smell of earth and diesel.

Tomorrow morning at 6:40, the bus along the old national highway would pull in on time. He would shoulder this bag, walk up the gravel slope, make the transfer, walk another four hundred meters, and push open the door to Laboratory No. 3. His left foot would be slightly swollen. His money would be gone. Voltage fluctuations. Compressed time. Four lines wove together again in his mind, meshing, locking into place. There was no way back, and no need for one.

He closed the notebook. Slipped the pen back into his pocket. Turned and walked back. Twenty-five-centimeter strides. Avoid the puddles. Forward.