Bite (2/2)
After lunch, Gu Yilan kept his promise and took him up to the third floor.
Su Zesui had been there before while scouting for an escape route.
Trailing behind the man, he looked around curiously, wondering where his surprise wedding gift would suddenly pop out from.
Gu Yilan walked straight to a corner room in the hallway, pressed his thumb to the fingerprint lock, opened the door, and stepped aside to let Su Zesui see.
The moment his eyes landed on the room, Su Zesui froze in place, lips parted in awe. His eyes sparkled with unmistakable joy and delight.
Inside wasn’t the classic Ahoo-style “roses, balloons, candles” package. Nor was it the mountain of plushies he had imagined.
Instead—it was a brand-new physics competition lab.
Sleek, silver instruments glinted in the sunlight.
There were devices for mechanics, electricity, optics, thermodynamics—everything a physics student could dream of. It was a literal paradise for a competitive physics student.
“Is today…” Su Zesui gasped and covered his mouth. “International Physics Lab Day?”
“No.”
Gu Yilan made a mental note to never joke around in front of this kid again. All his teasing and scaring from before were now boomeranging back onto him.
Gu Yilan said calmly, “We got married. I should give you a gift.”
“Thank you, Brother.”
Su Zesui’s eyes curved into crescents as he touched a photon emitter, then a fiber optic instrument, “Wow~” after “Wow~” spilling from his lips as he grinned, showing two tiny tiger teeth.
Gu Yilan stared for a second. “You’re that happy?”
“Happy!” Su Zesui replied without hesitation, looking up at him.
No one had ever given him a gift before—let alone such an amazing one. He was so excited! He liked Mr. Gu even more now!
All the disappointment from last night—when Mr. Gu didn’t undress him—had completely vanished.
Looking at the brilliant physics equipment before him, Su Zesui clenched his pale fists. He had figured it out: if Mr. Gu hadn’t caught on yet, he would just have to take the lead.
Not a big deal~!
. . . . .
“The school’s internal physics competition is in about a month,” Gu Yilan said, half leaning against the doorway. “How’s your preparation?”
“I’ve reviewed all the fundamentals,” Su Zesui replied.
He had flipped through the entire prep book and recovered part of his pre-transmigration knowledge. Though he wasn’t back to his old level, he was at least confident he wouldn’t get a zero.
Gu Yilan nodded slightly.
“This year, First High won several gold medals at CPhO. With all the media attention, the school wants to make a name for itself. On the day of the internal competition, there’ll probably be a documentary crew and interviews.”
He glanced again at the boy’s strikingly eye-catching face and said, “Since you’ve been studying for the competition on your own and taking part in it, you’ll probably end up on the interview list. Be mentally prepared.”
Su Zesui was stunned.
He was afraid of interviews—and even more worried about messing up during the exam and getting “publicly executed” on TV. His parents and older brother, who had always supported him… they’d definitely be disappointed.
And he couldn’t handle that look of disappointment in their eyes.
“Brother… teach me.” Su Zesui instinctively turned to the man in front of him for help.
Gu Yilan raised an eyebrow. “Mm. Tomorrow’s Monday. I have to go to school. Come with me.”
Su Zesui lowered his head, fidgeting with the hem of his shirt, and muttered softly, “I wish Brother would… lock me up.”
He thought back to the peaceful life he had when he first moved in—chained by the bedpost, with only one room as his activity range. He didn’t want to go outside.
Every time this topic came up, it would bring a heavy atmosphere. Seeing the boy hovering around the optical instruments, Gu Yilan decided to change the subject with a question: “What are the properties of light?”
Su Zesui looked up, instinctively straightening his back, and answered seriously as if responding to a teacher, “Wave-particle duality.”
“Waves are continuous energy. Particles are individual units. So how can light be both a wave and a particle at the same time?” Gu Yilan asked again.
Su Zesui couldn’t answer.
He only knew that textbooks said light had the properties of both waves and particles—that’s why it had wave-particle duality.
But how could something be this and that at once—especially when those two things are completely different? It was too abstract. He just couldn’t wrap his head around it.
He had done the double-slit interference experiment in the lab before.
He had directed light through two slits, creating two light waves. Just like ripples on water, the two waves interacted, producing alternating bright and dark fringes on a screen.
“If light is a particle, can we fire them one by one and observe the results?” Gu Yilan asked again, seeing the boy fall silent.
The question clicked something in Su Zesui’s mind, sparking his curiosity.
Particles move in straight lines—if you send them out one by one, waiting until one hits the board before firing the next, they should not display wave behavior. Instead, they should just form two bright lines parallel to the slits.
Excited, Su Zesui ran to close the curtains, then hurried back to fiddle with the photon emitter.
After a series of operations, he got his result—still alternating bright and dark stripes. It still showed the nature of light!
But… but those stripes came from the interference of two light waves. If there’s only one particle at a time, what is it interfering with? A ghost?
Su Zesui was dazed. He turned to Gu Yilan for help, wide-eyed: “Brother, why?”
“If you don’t get it, start by observing the process.” Gu Yilan walked to his side and took out a single-photon detector from nearby. He briefly introduced it: “It’s a camera that can capture the trajectory of light particles.”
Su Zesui had never seen such high-tech equipment before. He let out a soft “Wow” and couldn’t help reaching out to touch it.
“Here.” Gu Yilan grabbed his wandering hand and placed it on a certain part of the detector, guiding him to press a button. With a low hum, the device powered on.
While teaching him how to operate the machine, Gu Yilan was practically pressed against his back. When he spoke, the faint vibrations in his chest traveled right through to Su Zesui—and he was still holding his hand…
Su Zesui didn’t dare move a muscle. With his hand being held and pressed this way and that, he didn’t even dare breathe loudly, only taking small, shallow breaths for fear of scaring Mr. Gu away again.
Still, a tiny sense of pride bloomed in his heart—
Ahoo’s strategy guide was effective after all.
Look, he just acted a little cute in a voice recording, and now Mr. Gu was the one taking the initiative to hold his hand.
He had to keep it up! Let’s go!
“Did you understand?” Gu Yilan asked when he noticed the boy zoning out slightly, his hand going limp like it had no bones. He stepped back a bit, raising an eyebrow as he looked at the boy’s face.
“Y-yes, I understood.” In truth, Su Zesui hadn’t really been listening. But he had a good memory—just by thinking back a little, he recalled what the man had just said.
He set up the single-photon detector, aiming it at the possible paths the photons might take, then ran the experiment again—hoping to find out how a single photon could possibly interfere with something that doesn’t exist, ultimately creating an interference pattern.
“There.” The man’s long fingers tapped the screen. Su Zesui followed his gesture and instantly caught sight of the photon’s path.
Luckily, nothing spooky happened. They fired one photon, and only one photon showed up—no ghost photons interfering with it.
Su Zesui monitored each photon one by one, and after a long while, he looked even more puzzled as he turned to Gu Yilan and said, “Brother… they’re all normal.”
Gu Yilan clearly already knew what the outcome would be. He said, “Then go check the screen?”
Su Zesui nodded firmly, turned off the photon emitter, and picked up the photosensitive screen.
There were only two bright lines.
The alternating light and dark stripes had vanished. The wave-like nature of light had disappeared—only its particle nature remained!
But he hadn’t done anything. All he did was observe the path of the photons.
In that moment, Su Zesui suddenly remembered the teasing comment the man had made earlier: “There used to be a famous joke in the quantum community—‘When we’re not looking, the moon doesn’t exist.’”
When he didn’t observe, the photons behaved like waves, interfering with each other and creating an interference pattern. When he did observe, they acted like particles, forming only two bright lines.
No observation—wave behavior.
Observation—particle behavior.
So… if no one observes, does the moon disappear too?
Su Zesui scratched his head, his brain buzzing. But before he could recover, Gu Yilan coolly added fuel to the fire: “I think, therefore I am.”
“Brother, brother…” Su Zesui ran up to him, tilted his head back, and looked up at him with pleading eyes, like someone begging to know the answer to a riddle. In a soft and sweet voice, he said, “Tell me.”
A faint curve tugged at Gu Yilan’s lips. “Alright. Come with me to the lab tomorrow.”
His curiosity and thirst for knowledge had washed away some of his fear of the outside world—but Su Zesui was still scared.
Because there were a lot of people in the lab. Way too many.
“Can’t you just…” Su Zesui whispered, struggling, “tell me here, at home?”
“You have to go out eventually.” Gu Yilan’s heart was hard as ever. “I’ll be there. No one will touch you.”
Su Zesui puffed up his cheeks in protest, feeling wronged. He opened his arms, clearly asking for a hug.
Gu Yilan sighed inwardly, helpless, and finally bent down to let the boy hug him.
Based on how deeply insecure Su Zesui seemed, he guessed that the boy had probably witnessed serious violence as a child—or maybe even been a direct victim of it…
The boy’s body was light and soft. He stood on tiptoe, burying his head against Gu Yilan’s neck, his dark hair gently brushing back and forth. So obedient. So quiet.
Thinking about what the boy might have gone through, Gu Yilan suddenly felt a sharp jolt in his chest, like electricity. A brief stab of pain, then a spreading numbness.
But that emotional ache quickly faded—because he began to feel physical pain.
Gu Yilan gave a soft “tch” and tilted his head slightly to look toward where the pain was coming from—only to see Su Zesui, baring a tiny canine tooth like a little puppy, biting the back of his neck.