The heater in the car was on full blast. The windshield wipers swung tirelessly, like a pocket watch used for hypnosis.
Yu Xian leaned against the car window, the cold glass pressing against his temple.
’He had expected this, really. It was always going to be hard for his cousin to believe him, but he didn’t know who else to turn to.’
’Why did Xia Li disappear? And why was he the only one who remembered?’
The traffic light at the intersection turned red, and the car slowly came to a stop.
Yu Zhengze gripped the steering wheel with both hands, his eyes fixed on the curtain of rain ahead. He broke into Yu Xian’s thoughts.
"Xiaoxian, have you ever seen the movie *A Beautiful Mind*?"
Yu Xian wasn’t particularly interested. His gaze drifted slowly with the falling rain.
"The one about the Nobel Prize-winning mathematician? I only saw the beginning. Why?"
Yu Zhengze nodded.
"That’s the one. The genius mathematician, Nash, had schizophrenia. His mind created an imaginary friend for him—Charles—who kept him company through his toughest days. But later, after he got treatment, he gradually realized those people weren’t real."
Yu Xian hadn’t finished the movie, but he did remember the protagonist having a close roommate. He never would have guessed the roommate was an illusion, not a real person.
He understood the implication of Yu Zhengze bringing up the film.
"Cousin, do you think I imagined Xia Li?"
"I’m not sure." Yu Zhengze paused before continuing.
"But in our field, criminal investigation, there’s a famous French criminologist, Lokar, who proposed a widely accepted principle: ’Every contact leaves a trace.’ This theory is one of the foundations of modern forensic science."
Yu Xian turned to look at Yu Zhengze. His cousin’s gaze was gentle, but also firm.
"You study physics, and I’m a criminal investigator. We both believe in empirical science, right? If a person named Xia Li truly existed, there would definitely be traces of her."
He didn’t respond, but in his heart, Yu Xian agreed with Yu Zhengze’s logic. That was precisely what he couldn’t wrap his head around.
’If Xia Li’s disappearance was a magic trick, the method was far too crude.’
’A person who had been alive for nearly twenty years.’
’Her daily life, the meals she cooked, the classes she attended, the homework she submitted, the pictures she drew, the photos she took, the things she bought, the books she borrowed, the posts she’d liked—’
’all these things formed a dense, intricate web of threads of varying thickness connecting her to the world.’
’To make Xia Li disappear completely meant cutting every single one of those threads.’
He couldn’t help but think of that cliché analogy:
A butterfly flapping its wings can cause a storm on the other side of the ocean.
Even when you erase writing, you still leave a faint impression on the paper.
’So how could a living, breathing person vanish without causing so much as a ripple?’
’Even weirder, was he the only one in the audience for this magic trick?’
Yu Zhengze spoke again, his tone casual, as if making small talk.
"I was at a training seminar at the provincial department a while back. A criminal investigation expert gave a lecture and said something interesting: ’When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.’"
"Sherlock Holmes said that. I know."
Yu Zhengze glanced at him.
"Right now, we have zero information on Xia Li. A lot of hypotheses just don’t hold up."
Yu Xian’s gaze shifted back to the world outside the car.
"You’re trying to say that after eliminating all other possibilities, the only one left is that there’s something wrong with my mind, right?"
"I didn’t say that." Yu Zhengze sighed.
"But even if that were the case, there’s no shame in it. We could go talk to a professional, get an evaluation."
"Cousin," Yu Xian didn’t want to explain anymore. "I know what I’m saying. Xia Li isn’t someone I made up."
"Okay, then let’s just say I was overthinking it." Yu Zhengze fell silent for a moment, then spoke again slowly.
"Go home and get a good night’s sleep. Maybe one day you’ll just forget about all this, like it was a dream. What do you say?"
Yu Xian lowered his gaze.
’If what his cousin said was true, it would only mean things were even more wrong than he’d imagined.’
The car rolled to a slow stop in front of Yu Xian’s house. Yu Zhengze turned off the engine but didn’t immediately open the door. He turned to look at Yu Xian.
"Xiaoxian, I just want to help you. If Xia Li really exists, I will find proof. But if..."
"But if she doesn’t," Yu Xian finished for him, offering a tired smile.
"You’ll take me to a hospital, right?"
He didn’t wait for Yu Zhengze’s answer. He pushed open the car door, and a gust of cold wind and fine rain instantly flooded in.
"Thanks for the offer, Cousin. I’m fine, really."
Yu Xian left. Yu Zhengze sat in the car, lit a cigarette, and took a long, hard drag.
The glowing tip of the cigarette flared and faded in the dim car. Through the rain-blurred window, Yu Xian’s figure receded into the distance.