The alarm was still blaring, and the red light flickered across the wall, like someone repeatedly pressing a broken switch. Chen Hao's hand remained above the incubator, his fingertips just a centimeter away from the chick that had just sneezed. He didn't pull back, nor did he move forward.

"You just said there's a virus in the air?" His voice was a little dry, like a loudspeaker just dug out of a sand dune.

“Trace amounts of free particles have been detected.” Nana stood three steps away, her robotic arm slightly raised, the optical lens pointed directly at the incubator. “The high-temperature sterilization program will start in thirty seconds.”

"Wait a minute." Chen Hao took a breath. "Can we stop sending it to the execution ground so easily? It's only just opened its eyes; it hasn't even set its goals yet."

“Biosafety protocols take precedence over individual emotional assessments,” Nana said calmly. “Procedure countdown: 25 seconds.”

“Then let me ask you,” he suddenly turned his head, “last time after the pepper bomb went off, the bees were almost wiped out, why didn’t you just bury all the pesticide cans?”

Nana paused slightly in the shot: "Because there is room for adjustment and optimization, and no irreversible ecological collapse has been caused."

"That's it!" Chen Hao slapped his thigh. "That settles it, doesn't it? It hasn't caused any irreversible damage yet—it hasn't infected anyone else, and we're not dead, which means there's still hope! How about this, let's freeze the eggs first, and this little one... let's isolate and observe it for a few days, okay?"

“Isolation needs to meet Level 3 protection standards.” Nana quickly listed the parameters, “This cannot be achieved under the current environment.”

“Then let’s make it happen.” He stood up, wiped his face, and said, “At worst, I’ll convert the storage room into a negative pressure room, install fans, lay duct tape, and lay disinfection channels. Whatever you say, I’ll do it. If it really gets sick in three days, or transmits something else, I’ll personally put it into the incinerator, okay?”

The alarm suddenly stopped.

The red light went out, and the room returned to its stark white lighting.

"The agreement is temporarily suspended." Nana retracted the robotic arm. "Activate 'observational prevention and control mode,' and assume all risks."

"Thanks." Chen Hao grinned, then frowned. "But speaking of negative pressure, what is it? Does it mean the air pressure inside the room is lower than outside, so the wind can only blow in and not out?"

“Correct.” Nana brought up the simplified diagram projection. “It can be simulated using a one-way exhaust fan and a sealed structure.”

"Isn't that just a range hood with a plastic sheet?" He scratched his head. "Will our kitchen one still work?"

"It has been out of use for 473 days, and the filter clogging rate is 91%."

"Let's fix it." He rolled up his sleeves. "Anyway, I'm not going to get any sleep tonight."

For the next eight hours, the living area resembled an old, disassembled radio. Chen Hao removed the fan from the discarded air purifier and hung it upside down on the storage room door frame. He then pulled out several rolls of transparent plastic sheeting and used a hot glue gun to seal the cracks in the walls. Three layers of waterproof tape were applied to the seams of the floor. A five-centimeter gap was left at the bottom of the door, and a spring-loaded rubber strip was inserted, causing the door to automatically spring open when opened and close perfectly when closed.

"The pseudo-negative pressure system is now set up." Nana confirmed after scanning. "The airflow direction is stable and meets the basic isolation requirements."

"Wow." Chen Hao sat on the ground, panting. "The next step is the disinfection tunnel, right? What did you say before—change shoes, spray, put on gloves?"

“The three-level traffic flow design is complete.” She pointed to a corner of the kitchen. “This area is designated as a buffer zone and equipped with a foot-operated alcohol spray device.”

“I’ll do it myself.” He got up, found an old mop bucket, connected a hose and nozzle, and then modified a bicycle brake valve with a foot pedal to control the switch. “Just step on it and it sprays, no need to touch your hands, perfect.”

"The recommended alcohol concentration is 75%," Nana cautioned. "Too high a concentration can leave residue, while too low a concentration is ineffective."

“I remember.” He picked up two buckets of the prepared liquid. “One last round of disinfection, then we’ll move.”

He pushed the cart around the area, spraying the alcohol vigorously at the corners, doorknobs, and floor seams. The smell of alcohol quickly filled the air, making people's noses sting. Nana followed behind, testing the area and nodding in confirmation at each spot.

"The ventilation opening is up to standard."

"Ground microbial load has dropped to a safe threshold."

"The pressure difference in the buffer zone is normal."

"It's done." Chen Hao took off his mask and let out a long breath. "Son, Dad has built you a new home."

He carefully opened the incubator, wrapped the wobbly chick in a tissue, and placed it into the prepared isolation box. The box was a modified old medical pod, with insulation cotton lining the inner walls, dry grass at the bottom, and a miniature camera and temperature and humidity sensor on top.

"Vital signs monitoring has been integrated into the main control screen." Nana synchronized the data, "Respiratory rate, body temperature, and activity level are being tracked in real time."

"That's great." He leaned against the wall, looking like a deflated tire. "Now we just have to wait for it to grow up healthy, lay eggs, hatch chicks, and start a new era of coexistence between humans and chickens in the apocalypse."

As soon as he finished speaking, a "beep" sounded from above.

"Warning." Nana looked up. "The automatic spraying system is malfunctioning. The valve is continuously open, and alcohol is leaking."

Chen Hao jumped up suddenly: "Which part?"

"The foot valve connection line in the buffer zone is damp and short-circuited, causing the liquid supply pump to malfunction." She quickly located the problem. "The alcohol has now overflowed the ground and is seeping into the bottom of the control panel."

He rushed over and saw that white foam had appeared at the bottom seam of the half-meter-high electronic cabinet, and liquid was climbing up the cable tray.

"Turn off the power!" he roared.

With a flick of Nana's finger, all power in the vicinity was cut off.

"Towels!" Chen Hao rummaged through drawers and pulled out three dry cloths, stuffing them into the gap under the control panel. "You keep an eye on the steam concentration, I'll turn off the main valve!"

He crawled behind the control panel, found the manual knob on the supply tube, and tightened it forcefully. The alcohol flow finally stopped.

"Danger." Nana's voice was low. "The current concentration of alcohol vapor has reached 68% of the lower explosive limit. Any electrical sparks are strictly prohibited."

"I know." He slumped to the ground, still clutching a soaking wet towel in his hand. "What do we do now? Wait for it to evaporate on its own?"

"I suggest turning on natural ventilation and avoiding the use of electric equipment." Nana pulled up the building's structural diagram. "You can pry open the ventilation panel on the east side of the floor to accelerate air circulation."

Chen Hao grabbed a wrench and quickly removed the two floorboards. The night breeze blew in, carrying the earthy smell after the rain, slowly carrying away the pungent odor in the room.

"Is the surveillance still working?" he asked.

“The main system is still running, but prolonged immersion of the console may cause motherboard corrosion.” Nana stared at the data stream. “It is recommended to complete the drying and repair within seventy-two hours.”

"I'll fix it." He wiped his face. "At worst, I'll take the motherboard out and put it in the sun to dry."

"This method does not comply with electronic equipment maintenance standards."

“But it fits the survival norms of the poor.” He grinned, then composed himself and stared at the little chick curled up in the corner on the screen. “As long as it’s alright, everything else is negotiable.”

Time passed slowly, and a breeze seeped in through the cracks in the floorboards, dispersing the last wisps of the alcohol smell. Nana continued to report the environmental data every five minutes.

"The steam concentration dropped to 41%."

32%.

"twenty three%."

Chen Hao leaned against the wall, his eyes never leaving the screen. The chick stirred, raised its head, and chirped at the camera.

He smiled, reached out to touch the screen, then pulled his hand back.

"Don't move around," he whispered. "We finally managed to save you, we can't let anything else happen to you."

Nana suddenly turned to him: "You just said this is your son?"

“Hmm.” He nodded. “Although it probably thinks I’m a stupid dad.”

“The definition of parent-child relationship is usually based on blood ties or legal adoption.” Nana paused, “but in the human behavior database, there are cases of ‘emotionally projective kinship identification’, accounting for about 12.7%.”

"so what?"

“No conclusion.” Her optical lens flickered slightly. “It was just a record of an atypical social behavior sample.”

"Remember it as you like," he waved his hand. "Whether it recognizes me or not is unimportant; what's important is—"

Before he could finish speaking, the screen suddenly flickered.

Inside the isolation box, the chicks were gently pecking at the glass wall with their beaks, their movements slow but continuous.

“Abnormal behavior triggers alarm.” Nana responded immediately. “The pecking frequency exceeds the threshold of normal exploratory behavior, suggesting possible nervous system involvement.”

Chen Hao suddenly stood up and leaned closer to the screen.

The chick's eyes were slightly red, with a little discharge at the corners of its eyes, and its left leg was slightly stiff when it walked.

"Is it... a viral outbreak?" he asked in a low voice.

“Not yet confirmed.” Nana activated high-definition camera tracking. “Behavioral pattern comparison is underway.”

Chen Hao stared at the little creature that kept banging on the glass, his fingers unconsciously picking at the bits of tape on his knee.

“If it really is a virus,” he murmured, “is our quarantine about saving it, or is it about trapping it?”

Nana did not answer.

At the bottom of the console, the last drop of alcohol slid off the edge of the cable tray and hit the floor with a sound so faint it was almost inaudible.