Chen Hao placed the sample box on the ground; it was still smoking, like a hot iron just pulled from a pan. He quickly withdrew his hand, hissing, and shook his burning fingertips.

“This isn’t gathering herbs,” he muttered, “it’s more like developing biological weapons!”

Nana crouched down, and the robotic arm gently opened the container seal. Blue light flashed rapidly in her eyes. "The activity of the 'Centella asiatica' juice is stable, the 'Lithops' dryness meets the standard, and the extract from the roots of 'Blue Sprout' is not oxidized." After reporting the data, she looked up and said, "We can begin extraction."

"Easy for you to say." Chen Hao rummaged through his medical kit and pulled out an empty glass syringe and several sealed bags. "Our equipment is even more rudimentary than what elementary school students do in science experiments."

“Low-temperature distillation doesn’t require complicated equipment.” She took out a metal sheet and used a cutting blade to cut it into a shallow basin shape. “It just needs to be able to collect the volatile gases and condense and recover them.”

"You really think I'm the chemistry class representative?" He took the metal basin, weighed it in his hand, and said, "Fine, I'll be in charge of starting the fire, and you'll be in charge of reading the instructions."

Nana placed the stem segments of the flax vine into a basin, covered them with water, and then placed another bent metal piece diagonally on top, weighing it down with a cold stone—and the makeshift condenser was complete. Chen Hao lit a small pile of dry moss, carefully lifted the entire device, and placed it above the flame.

"The temperature should be controlled at around 60 degrees Celsius," she said.

"Why don't you specify how many fires there are?" he frowned. "I didn't bring a thermometer to this desolate planet for a campfire."

"Stop heating when the flame turns yellowish."

"Oh, so you're going to read people's faces?" He scoffed, but still did as he was told.

Smoke rose slowly, not black, but with a bluish-gray tinge, smelling like burnt pine resin mixed with rotten onions. Tiny water droplets gradually condensed below the condenser, sliding down the slope into the spare test tube.

"The first drop has come out." His eyes lit up.

"The active ingredient is a mixture of α-pinene and terpenoids, with a concentration of about 12 percent." Nana caught the liquid and poured it into a sealed bag. "The next step is to mix it with bluegrass extract."

They filtered the juice from the grass roots that had been soaked in water the day before and mixed it with distillate. The liquid immediately became cloudy, like leftover rice water. Finally, they sprinkled in powdered litmus and stirred it well, turning the whole thing into a grayish-white milky substance.

"Can this stuff be sprayed?" Chen Hao shook the bag; it was sticky and clinging to the inside.

“The adhesion is enhanced, but it needs to be diluted before use.” She took out the nebulizer—originally a respiratory medication device for emergency use, now converted into a handheld spray bottle.

He unscrewed the cap and tried it out. He pressed the airbag, and with a "pop," half a clump of foam was directly smeared onto his face.

"Oh my god!"

“The pressure regulating valve has malfunctioned,” Nana said calmly. “I suggest manually squeezing it slowly.”

"You make it sound so easy, my arm is practically cramping from shaking." He wiped the foam off his face, found his skin was a little itchy, and quickly rinsed it with water. "Won't this lousy medicine ruin my face?"

"The corrosiveness has been greatly reduced, and short-term contact is harmless."

“You really do always say ‘harmless’.” He rolled his eyes. “Last time you said wood ash wouldn’t affect the soil, and the next day the soil was as hard as cement.”

"This formula has undergone three simulation tests."

"Then why don't you tell me the simulation results?"

"After 87 seconds, more than 90% of the target insects stopped moving."

"...Pretty impressive." He grinned. "Alright, let's try the real thing then."

The two returned to the edge of the planting area. Sure enough, the three seedlings had been gnawed and pitted, with fine serrations covering the edges of their leaves, as if someone had used a needle and thread to pick at them.

"Right here." Chen Hao squatted down and sprayed a small circle of liquid onto the back of the leaf. The misty liquid landed on it, making a slight "hissing" sound, and then spread into a thin film.

Nana activated infrared monitoring, and soon more than a dozen tiny heat sources appeared in her field of vision, slowly approaching.

"They're here."

The insects are gregarious, about the size of a sesame seed, dark brown all over, with six legs that move swiftly, appearing as a string of jumping red dots in an infrared image. When they approach the seedlings, they suddenly stop, their antennae tremble, then they abruptly turn around and scatter in panic.

"Works?" he stared.

“Some individuals showed delayed neurological responses.” She zoomed in on the image, “Two of them spun around in place for more than ten seconds.”

"Hahaha!" He slapped his thigh. "Ours is a completely natural green pesticide, zero additives, no residue, and it's all about being environmentally friendly and powerful!"

"Please don't get too excited," she cautioned. "The total amount of medication is only enough to cover one-third of the area."

The laughter stopped abruptly.

“…That’s true, we can’t just be having fun and forget about our supplies.” He put away the spray bottle and looked at the remaining medicine bags. “We need to use them sparingly.”

According to Nana's calculations, spraying 0.8 milliliters per square meter is optimal. More is wasteful, less is ineffective. They decided to adopt a "spraying every other row + border control" strategy—first drawing a circle around the planting area, then treating a row of seedlings every other row to form a staggered protective net.

Chen Hao carried the pesticide bag in one hand and the spray nozzle in the other, slowly advancing as if watering a lawn. After spraying each spot, Nana followed to scan and confirm. As time passed, the insect swarm's activity range continuously shrank, eventually retreating deep into the rock crevices.

"Two rounds of spraying are complete." She put away the detection module. "The current insect population density has dropped to eight percent of its peak, and no new signs of feeding have been found."

He let out a long sigh, plopped down on the muddy ground, and leaned against the rock wall.

"Finally... I feel at ease." He looked up at the cave ceiling. "Don't you think these insects are a bit wronged? They were living perfectly fine, and then suddenly a poisonous mist sprayed out, scaring them so much that they didn't even dare to go home."

"In an ecosystem, predation and defense are inherently two-way mechanisms."

“But we’re the victims here,” he said with a wry smile. “Is it easy for me to grow vegetables? I have to dig ditches, stay up all night, and keep away from giant slugs checking my records. Now that I’ve finally made some progress, I have to consider the feelings of the insects.”

Nana didn't speak, but stood quietly to the side, her blue eyes flashing steadily.

He glanced down at the last empty spray bag and tossed it into his backpack. Dirt clung to his fingernails, his cuffs were covered in dried medicine stains, and faint white marks from the spray remained on his face.

But he was laughing heartily.

The land finally quieted down. The tender shoots unfurled gently in the dim light, untouched by anyone. The wind was silent, save for the rhythmic patter of distant raindrops, one after another, like a steady heartbeat.

“We can finally get a good night’s sleep in our vegetable garden,” he said softly.

Nana performed a final scan, and the data panel displayed: Threat Level - Low.

She retracted the robotic arm and was about to speak when her gaze suddenly sharpened.

"What's wrong?" He sensed something was amiss.

"There is a slight change in humidity on the east side of the rock face."

"So what if it's a little wet? It's not like it's going to rain."

“The pattern of change does not conform to the natural seepage law.” She took a few steps closer and placed her palm on the rock. “It’s rising continuously and is concentrated at the three o’clock position.”

Chen Hao also stood up and walked over to touch the wall. He felt a coolness on his fingertips, but what was even stranger was that the moss in that area seemed to be a darker color than the rest.

"Could it be... that something else is about to pop out again?"

"It's impossible to determine at this time," she said, "but I recommend increasing vigilance."

He stared at the wall for a long time, then sighed.

"Can't you let me rest for a while?"