Chen Hao's shoulders were still aching, and the metal scraps in his tool bag clinked softly with each step. He had just finished walking the last stretch of the field ridge; the sun was already low on the horizon, casting a long shadow. He looked down at the newly turned earthen mounds at his feet, and the weariness in his heart was finally somewhat suppressed by a sense of accomplishment.

Just then, Nana's voice suddenly rang out, without any prelude or buffer: "Large-scale insect migration signal detected, characteristics match desert locust, distance 87 kilometers, estimated arrival time 11 hours and 53 minutes."

Chen Hao suddenly stopped, almost tripping over his own shoe. He turned to look at the field—a patch of land that had just been loosened, fertilized, and where the seedlings hadn't even fully emerged yet, like a freshly laid-out sheet of white paper, clean and completely unguarded.

"It's over," he muttered. "It's really over now."

He slammed the iron plow into the ground, casually tossing the tool bag off his shoulder, not even bothering with the metal fragments inside. "These things arrive more punctually than takeout, but we have no food here, only grass sprouts!"

Nana stood still, the terminal screen had switched to a holographic red screen, and a moving band of light was approaching the cultivated area along the virtual map. "Flying altitude of 300 to 500 meters, population density of about 4.2 million per square kilometer, possessing strong feeding ability and continuous migration characteristics."

"You mean, they're not just passing by, they're here for food?" Chen Hao wiped his face, sweat mixed with dirt leaving deep lines on his skin. "I worked so hard turning the soil and fertilizing, and it turned out to be a buffet for locusts?"

“The logic holds true.” Nana nodded. “Currently, the crop seedlings are in their most vulnerable stage, lacking natural defense mechanisms. Without intervention, the expected loss rate is close to 100%.”

Chen Hao plopped down on the edge of the field, took a couple of breaths, and then jumped up suddenly: "No, we can't just sit here and wait to die! We have chili peppers and garlic, we can't just let them eat their fill, can we?"

He dashed towards the storage shed, shouting back as he ran, "Get containers! Stirring up the pot! Bring out the grinder too! We're not sleeping tonight, we're launching a spicy counterattack!"

---

The laboratory lights were blindingly bright.

Chen Hao pulled three strings of dried chilies from the shed, snapped them off, and the red seeds clattered into a stainless steel basin. He then grabbed half a basket of garlic, his fingers turning bright red from the spiciness as he peeled them, and he couldn't help but blow on them.

"You think this thing really works?" he asked Nana, looking up at her. "I remember when we were kids, we used to chase grasshoppers in the village with gongs, drums, and firecrackers. Who ever used pepper spray?"

Nana's robotic arm was adjusting the centrifuge. "According to database records, capsaicin can stimulate the nerve endings in the antennae of insects, causing an adverse reaction; allicin can interfere with their olfactory recognition system, reducing their foraging ability." She paused, "The combined effect is even better."

"It sounds like we're giving them a hot pot, so spicy they won't want to eat." Chen Hao grinned as he poured the crushed garlic into the pot. "Then let's add extra spices, so they'll never forget it after just one bite."

Flames licked the bottom of the pot, the medicinal liquid gradually boiled, and a pungent aroma quickly filled the air. Chen Hao coughed as he stirred, tears welling up in his eyes. "This smell... is even worse than the last time I ate those super spicy potato chips, it's practically a biological weapon."

"I recommend wearing a protective face shield." Nana handed over a simple mask.

“Wearing it won’t help; the smell just goes into your nostrils.” He waved his hand and continued stirring. “Besides, what soldier deserts in the face of battle? At most, it’s considered a minor injury that keeps them on the front lines.”

The liquid changed from cloudy to a thick, dark red color, with a layer of oily sheen on the surface. After taking a sample for testing, Nana confirmed: "The active ingredients meet the standards, and it is preliminarily determined to have repellent properties."

"Great!" Chen Hao slapped his thigh. "Bottle it right away and spray it until nothing is left!"

The two poured the pesticide into handheld sprayers and rushed to the fields that night. The night breeze was cool, but a pungent, spicy smell still lingered in the air. Chen Hao carried the sprayer back and forth, as if he were vaccinating the crops, leaving no inch of land untouched.

"After spraying this round, let's see if they dare to come again!" He panted, wiping the sweat from his forehead. "Am I doing farm work or epidemic prevention?"

Nana stood at the edge of the field recording data: "The spraying coverage has reached 68 percent, and the remaining area can be completed within two hours."

Chen Hao nodded and was about to continue his work when he suddenly heard her voice change: "Warning, abnormal detection."

He turned around: "What's wrong?"

“The pH value of the surface soil in the sprayed area has dropped sharply, currently at 4.1, which exceeds the tolerance range of most crops.” Nana pulled up the analysis chart. “If the exposure continues, the seedling roots will suffer irreversible damage within 48 hours, and the mortality rate is estimated to be 90%.”

Chen Hao was stunned: "Wait...you mean, the medicine we painstakingly prepared isn't for killing insects, it's for poisoning the soil?"

“The conclusion is valid.” Nana pointed to the screen. “During the high-temperature cooking process, the sulfides in garlic are converted into sulfurous acid, which combines with chili oil resin to form a highly acidic mixture that is corrosive.”

"So all that work was just about splashing toilet cleaner on the field?" Chen Hao's eyes widened. "No wonder it smelled so pungent, it's a chemical accident scene!"

"Correction: This was not intentional; it's a flaw in the formula design." Nana's tone remained calm. "The current priority is to adjust to protection and remediation. We recommend immediately suspending spraying and re-optimizing the ingredient ratios."

Chen Hao plopped down on the edge of the field, still clutching the sprayer handle. His face was blackened by the smoke, and his nose was bright red, as if he had just escaped from a kitchen explosion.

"I should have planted mint," he muttered. "I heard locusts hate the smell of mint, and it doesn't hurt the soil. That would have been great."

“Mint has a long growing cycle and cannot replace existing crops at this stage,” Nana cautioned. “Furthermore, its volatile components only have a slight repellent effect on some insects, and the effect is unstable.”

"Alright, alright, it's my fault for being ignorant and making impulsive innovations." He sighed and looked up at the dark sky. "What do we do now? There are only nine hours left before the locusts arrive. We can't spray the ground or protect the seedlings. Are we really going to just watch them devour all our hard work?"

“There’s still room for improvement.” Nana turned and walked toward the lab bench. “We could try a low-temperature extraction method to avoid generating harmful substances from high-temperature reactions. We could also add a neutral buffer to adjust the pH.”

"Then hurry up and do it, I'll help you." Chen Hao struggled to stand up, his legs still a little weak. "Even though I'm a terrible student, I can still copy homework."

---

The laboratory is back in operation.

Nana dismantled the original process and switched to a cold soaking method to extract capsaicin. She also diluted the garlic paste and stirred it at low temperatures to prevent excessive conversion of sulfides. She added a small amount of baking soda to the solution as a buffer and monitored pH changes in real time.

Chen Hao squatted beside the beaker, staring at the liquid that was slowly clearing up, and asked cautiously, "Won't it turn into poison again this time?"

"The current pH value is stable at 6.3, which is within the safe range." Nana scanned the data. "The active ingredient retention rate is 78%, and the expected repellency efficiency can reach 70% of the ideal value."

"Seventy percent is better than nothing." He breathed a sigh of relief. "As long as I don't see the words '90% mortality rate' again, I'm willing to kowtow to it."

The pesticide was refilled into the sprayer, and the two returned to the field. This time, they sprayed with extra care, repeatedly checking the parameters for each area. The night breeze swept across the field ridges, carrying a faint, pungent aroma, but no longer the acrid smell of before.

By the time the last area was finished being sprayed, the sky had already turned grayish-white.

Chen Hao put the sprayer on the ground, and collapsed onto the edge of the field as if all his bones had been removed. "I feel like the air I'm breathing right now could choke a mosquito to death."

Nana stood beside him, her optical lens scanning the entire field. "Spraying task complete. System entering monitoring mode. Time remaining: nine hours and seventeen minutes."

"You still remember the countdown?" Chen Hao rolled over and looked at her. "Couldn't you have said something else? Like 'You've worked hard' or 'Go get some sleep'?"

"The current risk level has not been lifted, so it is not advisable to enter hibernation mode." Nana looked down at him. "Your eyelid tremors are more frequent, indicating extreme fatigue. I suggest you close your eyes and rest for fifteen minutes."

"Fifteen minutes? By the time I wake up, the locusts will have finished their meal." He propped himself up on the ground, grabbed half a chili stem and put it in his mouth. "Whatever, I can't sleep anyway. If they really come, do you think I can fight them with a spatula?"

Nana didn't answer, but suddenly turned to look at the distant horizon.

Her terminal screen flickered again, but this time it wasn't a red alert; instead, it displayed a rapidly scrolling stream of data.

Chen Hao noticed her movement and looked over as well.

As dawn breaks, the fields are silent, and the wind sweeps across the newly sprayed furrows, carrying a lingering spiciness.

Just as he was about to speak, Nana raised her mechanical arm and pointed it to the sky.

His mouth stopped in mid-air, and the chili stem he was holding fell down.