The semester finally, mercifully, crawled to its conclusion. The campus emptied out, the frantic energy of exams replaced by the hollow silence of winter break. For Lin Xiaoyang, the journey back to his hometown was not just a geographical shift; it was a system migration to a lower-stress environment. A chance to defragment his hard drive, to run a deep clean on his cluttered mental cache.
His hometown was a mid-sized city where time seemed to flow at half-speed. The air smelled of familiar street food and coal smoke, a stark contrast to the sanitized, high-tension atmosphere of university. For the first two days, he did nothing. He slept. He ate his mother's cooking. He stared at the ceiling. It was glorious. The Energy-Saving Principle was not just a philosophy here; it was the default state of existence.
On the third day, buoyed by a sense of restored equilibrium, he decided to venture out to the old bookstore he used to frequent in high school. It was a calculated, low-risk outing. The probability of running into anyone who would demand dramatic, logical, or mystical interactions was, he estimated, a comfortable 3.7%.
The bell above the door chimed with a soft, familiar ding. The smell of old paper and binding glue was a balm to his soul. He browsed the shelves, his fingers trailing over worn spines, a sense of profound peace settling over him. This was it. This was the efficiency he craved.
He reached for a specific volume on programming architecture he remembered from his senior year, a book that had first sparked his interest in efficient systems. His hand closed on the spine at the exact same moment as another's.
It was a slender, elegant hand. He knew that hand.
He turned his head slowly.
Standing beside him, her expression one of mild, unsurprised curiosity, was Shen Qinghe.
Time seemed to stutter. She looked exactly the same, yet different. Her hair was longer, cascading past her shoulders like a black waterfall. Her eyes, always calm and perceptive, held the same quiet intensity he remembered. She was wearing a simple, cream-colored sweater, and she smelled faintly of ink and osmanthus.
"Lin Xiaoyang," she said, her voice as soft and steady as he remembered. "You still favor the 2019 revised edition of Patterson and Hennessy's Computer Architecture. The spine is more worn on the left side, indicating you pull it from the shelf with your right hand, applying pressure with your thumb between the 'C' and 'o' of 'Computer'."
Xiaoyang's brain blue-screened.
He stood there, mouth slightly agape, his carefully restored energy reserves plummeting. It wasn't a dramatic crash, but a silent, catastrophic system failure. Of all the variables he had modeled for his hometown, this was the one he had deliberately, subconsciously, excluded from his calculations.
"Shen… Qinghe," he managed to stammer.
"Acknowledged," she said, a ghost of a smile touching her lips. It was the same phrase Su Yuning used, but it felt entirely different. Coming from Su Yuning, it was a system prompt. Coming from Shen Qinghe, it was… an affirmation. "I calculated an 83.4% probability of finding you here during the first week of break, between the hours of 2:00 and 4:00 PM. Your post-exam recovery pattern has remained consistent since high school."
She reached past him, her movements fluid and unhurried, and plucked the book from the shelf. "You were looking for the section on superscalar processors. Page 287. You have a habit of dog-earing the corner when you find a particularly relevant passage. This copy has seven such folds."
She handed him the book. He took it numbly.
Analysis: Impossible. Input exceeds processing capacity. Critical exception.
"How…" he began.
"How do I know?" she finished for him, her head tilting. "You told me. The third Tuesday of our final semester. We were studying for the mock exams. You said, 'A good book is like a well-indexed database. You should be able to find the data you need instantly.' You were drinking milk tea with less ice, and you had a small ink smudge on your left earlobe from your leaking pen. It was 4:32 PM."
Xiaoyang felt the world tilt. It was more than just memory. It was a perfect, high-resolution recording. Su Yuning remembered data. Shen Qinghe remembered… context. She remembered the entire system state.
"This is… inefficient," he blurted out, falling back on his core programming as a defense mechanism. "Storing that level of irrelevant detail."
"Is it?" she asked, her gaze unwavering. "It allowed me to find you, didn't it? And to retrieve the book you wanted with 100% accuracy. Efficiency can be measured in more than just processing cycles, Lin Xiaoyang. It can also be measured in the absence of wasted search queries."
She had just reframed his entire life's philosophy with a single sentence. He had no defense against this.
They left the bookstore together, walking along the familiar, slightly shabby streets. The silence between them was neither the demanding silence of Su Yuning nor the expectant silence of Chen Yuexi. It was a comfortable, shared buffer, like two compatible processes running in parallel.
He found himself telling her about university. About his app. He kept it vague, logical.
"Your 'EfficientHeart' project," she said, not looking at him but at a sparrow hopping on a power line. "It's an attempt to model human affection through deterministic pathways. A fascinating challenge."
"You think it's possible?" he asked, genuinely curious.
"Possible? Perhaps. But optimal?" She finally looked at him, and her eyes seemed to see right through his code, his principles, his carefully constructed walls. "Human connections aren't built on the most efficient path. They're built on the accumulation of insignificant details. The shared memory of a leaking pen, the taste of a specific brand of milk tea, the way sunlight falls through a bookstore window at 3:17 PM on a winter afternoon. These are the data points that a brute-force algorithm would discard as noise. But they are the very data that creates a unique key between two people."
Xiaoyang stopped walking. He felt like he had been struck by lightning. She had just articulated the fatal flaw in his app, and in his own life approach. He had been trying to filter out the noise, to find the pure signal. Shen Qinghe was telling him that the noise was the signal.
"It sounds… messy," he said, his voice quiet. "Inefficient."
"It is," she agreed. "It requires massive, unstructured data storage. But the recall is instantaneous, and the connection it forges is… unbreakable." She pointed to a small, hole-in-the-wall noodle shop. "You once said the beef noodles here were 17% more satisfying than the ones from the chain store next to our school. Because the owner's wife always gives you an extra pickled vegetable. Your optimal choice remains the same."
They went in. The owner's wife, a woman in her sixties with a kind face, beamed at them. "Xiaoyang! And… Qinghe! It's been so long! Your usual?"
As they ate the steaming, perfect noodles, Xiaoyang felt a sense of calm he hadn't experienced in months. There were no flags to raise, no probabilities to calculate, no auras to interpret. There was only the simple, undeniable efficiency of being known. Shen Qinghe's database wasn't intimidating; it was… grounding. She was a living backup of his own past, a testament that his existence, in all its trivial details, mattered.
He didn't need to explain his Energy-Saving Principle to her. She already had it filed away, alongside the memory of his preferred brand of pencils.
When they parted ways at the intersection near his home, she said, "Your internal state appears more stable than your university communications suggested. The environmental variables there—the 'Logical Overload,' the 'Theatrical Delusion,' the 'Mystic Assault'—seem to be causing significant resource contention."
He stared at her. "How do you know about—"
"You mentioned them in your texts. Albeit with less formal nomenclature." She adjusted her scarf. "My analysis suggests your system is attempting to multi-thread incompatible processes. It's no wonder you're experiencing performance issues." She gave him that faint, knowing smile again. "Sometimes, the most efficient solution is to close all other applications and return to a stable, legacy environment."
She turned and walked away, her figure receding down the street without a backward glance.
Xiaoyang stood on the corner, the cold winter air sharp in his lungs. The Hometown Variable, Shen Qinghe, had just connected to his system. And with a few simple queries, she had exposed the fundamental instability of his entire operational framework.
She wasn't another source of energy drain. She was a complete, self-contained, and terrifyingly efficient operating system all her own. And for the first time, his own "Energy-Saving Principle" felt not like a sophisticated life hack, but like a clumsy, resource-intensive workaround for a problem she had already solved.