Doomsday Mechanic: My Train Can Be Modified Infinitely

The person he was looking for was Lin Luo'er, twenty-three years old, a master's student in agricultural engineering, specializing in closed ecosystems and plant factory technology. This was a name from his past life memories—not from survivor rumors, but from a tattered experimental log he found in an abandoned shelter. The log's owner meticulously recorded the entire process of building a small closed ecosystem in an underground parking lot, mentioning "Lin's theory," "Lin's computational model," and "Lin's insistence on adding a nitrogen-fixing module from legumes" seventeen times. The last few pages of the log were illegible, mentioning, "Lin insisted on going to an abandoned nursery on the outskirts of the city to find more seeds... She said without genetic diversity, the system would collapse sooner or later... She left this morning, saying she'd be back in three days... It's the seventh day, and she hasn't returned."

A person with solid professional knowledge, the ability to translate theory into practice, and the courage and vision to take risks for long-term hope even in dire circumstances. This is exactly what Wang Zhengyang needs—not just a simple vegetable grower, but an expert who can design and maintain a life support system that can operate continuously in extreme environments characterized by movement, vibration, and limited resources.

More importantly, the information he found in the school's information system showed that Lin Luoer, female, born in 1996, is from Nanjing, Jiangsu Province. Her father, Lin Weimin, is a researcher at the Institute of Crop Genetics and Improvement of the Jiangsu Academy of Agricultural Sciences; her mother, Shen Jing, is the deputy chief physician of the Department of Respiratory Medicine at Gulou Hospital. She is an only child, studied at Nanjing Agricultural University for her undergraduate degree, and came to the Technical University of Berlin through an exchange program during her senior year. She achieved excellent grades during her master's studies and has published two SCI papers. Currently, she has applied for a doctoral program at her current university but has not yet chosen a supervisor, while also looking at several research opportunities in China.

Her family background gives her a natural inclination towards "formal employment" and "domestic development"; her academic ability ensures she can excel in technical work; and the personality traits implied by her experimental diary—persistence within rationality and courage within caution—make her a potentially reliable long-term partner.

The subway arrived. Wang Zhengyang followed the flow of people out of the carriage and onto the familiar cobblestone streets of the Technical University of Berlin's main campus. The autumn campus was beautiful; the plane tree leaves were beginning to turn yellow, the lawns were still lush and green, and students in various colors hurried by carrying books. All of this would be completely different in twenty-seven days. Wang Zhengyang suppressed the almost absurd sense of alienation in his heart and strode towards the College of Agriculture and Horticulture building.

At 10:15 a.m., in the corridor on the third floor of the Faculty of Agriculture and Horticulture at the Technical University of Berlin.

Wang Zhengyang waited in the corridor outside Laboratory 316. According to the schedule provided by Professor Hans, Lin Luoer would usually be in the lab processing morning experimental data at this time. He arrived five minutes early, leaning against the window, seemingly looking at the scenery outside, but actually using his mechanical affinity to sense his surroundings: the fire sprinkler system pipes on the corridor ceiling had slight corrosion, but it didn't affect their function; the electronic lock on the lab door had a complex internal structure, but the mechanical parts were worn; in the distance, he heard the footsteps of two students in the stairwell, one weighing about 65 kilograms and the other about 70 kilograms, with different stride frequencies…

The laboratory door opened.

A young woman in a white lab coat emerged carrying a stack of printed documents. She was about 1.65 meters tall, and even in the loose fit of the white coat, her slender yet upright figure was evident. Her shoulders were straight, her waist was cinched, and her legs, outlined in straight-leg trousers, hinted at their length. Her long, flaxen hair was loosely tied in a bun at the back of her head, secured with a simple wooden hairpin. A few stray strands fell loosely around her neck and ears, gleaming softly in the sunlight streaming through the window. She wore frameless, silver-rimmed glasses, behind which were clear, almond-shaped eyes with warm, light brown pupils. At that moment, she was slightly furrowed, staring at a data sheet in her hands, her lips unconsciously pursed, revealing a hint of her pearly upper teeth.

Wang Zhengyang's gaze lingered on her face for a moment longer than required by politeness.

She was beautiful, but not in a flamboyant, aggressive way; rather, she possessed a clean, scholarly elegance. Her skin was ivory white, so smooth that pores were almost invisible. Her nose was straight but not overly sharp, her lips were well-defined, and the corners of her mouth naturally turned up slightly, even when she frowned, there was an innate gentleness about her. But what attracted Wang Zhengyang even more was her serene temperament—like the steady operation of a precision instrument, rational, focused, and unique, subtly isolating her from the noisy campus environment.

When her gaze lifted from the data sheet and met Wang Zhengyang's, a flicker of annoyance at being disturbed flashed in her light brown eyes, quickly turning into wariness and questioning. Her eyelashes were long, fluttering like butterfly wings when she blinked.

"Lin Luo'er?" Wang Zhengyang took two steps forward and asked in standard Mandarin, while maintaining a polite social distance.

Lin Luo'er took a half step back, an instinctive defensive movement. "Who are you?" Her voice was clear and crisp, with a touch of softness from her Jiangnan accent, like a stream flowing over pebbles.

"Wang Zhengyang, visiting scholar in the Department of Mechanical Engineering." He took out his faculty card from the inside pocket of his suit jacket and handed it to her without putting it in her hand—a detail to reduce any sense of pressure. "I'm involved in the preparation of an interdisciplinary project about integrated life support systems in extreme environments. Professor Hans recommended you, saying you are one of the most promising young researchers in this field."

Upon hearing Professor Hans's name, Lin Luo'er's wariness lessened slightly. She freed one hand to take the ID, carefully examined the photo and name, and then glanced at Wang Zhengyang in comparison. This meticulous action showed that she was a detail-oriented person. "Professor Hans mentioned... the 'Deep Space Habitat Simulation Test Project'? He briefly mentioned it at the group meeting last week."

"To be more precise, it's the 'Integration and Verification Project of Closed Ecosystem and Heavy Transport Platform in Extraterrestrial Extreme Environments,'" Wang Zhengyang used the full project name, which sounds more formal and larger in scale. "We are currently conducting preliminary preparations in Germany and need to assemble an interdisciplinary team. The mechanical and structural aspects have already started, and we urgently need a professional who is proficient in closed ecosystem design, especially hydroponics, air circulation and regeneration, and organic waste treatment and conversion, to join the design phase. The project will last approximately six months, mainly conducting ground simulation tests in Germany. After completion, there may be opportunities to participate in subsequent related applied research in China."

He noticed a glint in Lin Luo'er's eyes when he mentioned "relevant applied research in China"—though she quickly concealed it, it didn't escape Wang Zhengyang's notice. It wasn't just interest; it was more like a deep-seated expectation.

"Could you... elaborate?" she asked, her tone less distant and more inquisitive.

Wang Zhengyang led her to the rest area at the end of the corridor, where there were several sofas and small round tables, and it was relatively quiet. He gestured for Lin Luo'er to sit down, while he sat on a single sofa to the side, maintaining a posture that was both conducive to communication and not overtly intimate.

He opened his tablet and pulled up several processed schematic diagrams that did not involve core secrets—a modular multi-layer hydroponic planting rack design, a simplified diagram of an air circulation system with activated carbon and photocatalytic units, a principle block diagram of a pyrolysis and gasification treatment device for kitchen waste and excrement, and a 3D model of a "heavy mobile platform" that was deliberately blurred and only showed its general outline.

"Simply put, we need to establish and maintain a small, closed ecosystem capable of supporting the basic survival needs of 80-100 people in a strictly confined space, with limited initial resources, and an external environment simulating extremely harsh conditions." Wang Zhengyang turned the tablet towards Lin Luoer, pointing at the screen with his finger. "This system needs to be highly self-sufficient, able to recycle more than 90% of its water and oxygen, produce at least 500 grams of fresh vegetables per person per day, and be integrated into a platform that can move, vibrate, and whose posture may change. You are an expert; you should know how severe the technical challenges are."