Genius Playground

”Scientists have many theories about time travel and the nature of spacetime.”

In their general studies class, the professor wrote on the blackboard:

”There’s a theory that our universe contains countless parallel spacetimes. Every tiny change or choice can split off into a completely different Worldline.”

”These similar yet different parallel spacetimes are like countless threads, starting from a single point and radiating out toward an unknown future, constantly splitting as they progress...”

”This is what we’re going to discuss today: the Worldline Theory.”

...

General studies courses were electives. All sorts of classes were available, with no restrictions based on major or college. Anyone could sign up as long as they were interested.

Jiang Ran rested his chin on his hand, eyes closed in deep thought.

Yesterday afternoon’s experiment had also failed.

The sixty consecutive text messages were all delivered to Cheng Mengxue’s phone without a single loss. The dizzying, world-spinning sensation he’d expected never came.

’Sigh.’

’Just why, though?’

’Why was it that only that single text message managed to travel through time? Why couldn’t he replicate it?’

He felt a poke.

Cheng Mengxue, sitting next to him, poked his elbow.

”Are you disappointed?” she asked, looking into Jiang Ran’s eyes.

”A little,”

Jiang Ran admitted.

”But I’m fine. I was prepared for this. If it were that easy to send texts to the past, the world would have been turned upside down long ago, right?”

Cheng Mengxue chuckled and pushed a piece of paper toward him.

”Take a look. I summarized the main points for you guys.”

Jiang Ran looked down at the paper. A title was written in large letters across the top:

”The Great Time SMS Incident! A Summary of Key Points!”

Pfft.

He couldn’t help but laugh.

Cheng Mengxue had started scribbling away the moment class began. He’d thought she was just taking diligent notes, but it turned out she was writing this.

”What did you write this for?”

”To help you organize your thoughts!”

Cheng Mengxue leaned in, her voice low.

”You’ve been looking so down all day. I knew you were thinking about that text message.”

”I couldn’t help much otherwise, so I just summarized the points you and Qin Feng discussed. I was hoping it might give you some inspiration.”

Jiang Ran chuckled softly.

”You’re really thoughtful. I’ll get you a little something next time we’re out shopping.”

”Could you buy me a Rhine Cat rice cooker?” Cheng Mengxue proposed.

”How much?”

”3,000.”

???

Jiang Ran sucked in a sharp breath.

”Why don’t you just go rob someone!”

”And good luck even finding one in stock!”

”Then let’s just wait until the hype dies down and it’s out of style.”

Jiang Ran huffed.

”This Rhine Cat thing isn’t going to stay popular for centuries, is it?”

...

It was hard to whisper in class, so Jiang Ran turned his attention back to the sheet of paper.

Her handwriting was neat and elegant.

She’d written down everything they had discussed at the boba shop the day before yesterday.

Back then, they had just been throwing ideas around. Seeing it all organized now made everything much clearer.

Timeline of Events

1. Afternoon of March 17: Cheng Mengxue loses her phone, finds Jiang Ran, and has him send a text message to her lost phone.

2. The text message unexpectedly travels through time, going back to the past and arriving on Cheng Mengxue’s phone on March 14.

3. The Jiang Ran of March 14 denies sending the text, but the Butterfly Effect begins. The original course of history is altered.

4. Thanks to the text’s warning, Cheng Mengxue is more careful with her phone. As a result, her phone is not lost on March 17. She never goes to find Jiang Ran, and consequently, Jiang Ran never sends the original text message.

5. The historical timeline changes, causing a shift in spacetime. From Jiang Ran’s perspective, this entire shift happens in two seconds. When he opens his eyes, both Cheng Mengxue and the text he just sent have vanished.

6. The most inexplicable issue: Jiang Ran retains memories from before the spacetime shift but has no corresponding memories from after it. He doesn’t remember the argument from three days prior.

”So, class, pay attention!”

The professor’s voice suddenly rose as he tapped the blackboard.

”This act of jumping from World Line A to World Line B is called a [Worldline Jump]!”

Many of the students who had been spacing out looked up toward the lectern.

”Of course, this Worldline Theory is just an unverifiable hypothesis.”

”Time Travel, you see, is considered a rather romantic concept, even in the serious field of physics.”

The professor put down his chalk and smiled.

”There are many similar hypotheses about spacetime. If you’re interested, you can look into them after class.”

”Class dismissed!”

...

The trio followed their usual route, arriving once more at the old spot next to the familiar transformer box.

Jiang Ran stared at the massive object, listening to the low buzz of the current.

”We’ve considered multiple factors—time, location, our positions, the direction we were facing...”

”But I think... we’re still missing some [key factors].”

Qin Feng followed Jiang Ran’s gaze.

”You’re not thinking of messing with the transformer box, are you? That thing belongs to the state grid. High voltage is dangerous, and besides, destroying it is against the law.”

”I’m not an idiot.”

As he spoke, Jiang Ran turned on his phone’s flashlight and peered through the vents of the transformer box.

Nothing out of the ordinary.

Inside was just a standard transformer.

The device’s purpose was to convert tens of thousands of volts of high-voltage electricity into low-voltage power for daily use. The whole campus was full of them.

It was peak electricity usage time, so the transformer box felt slightly hot to the touch and was filled with the noise of the equipment inside.

A thought suddenly occurred to him.

He thought about the sci-fi movie *Terminator*. Every time a robot arrived from the future, it was accompanied by a massive electrical discharge, with blue arcs of electricity crackling everywhere.

And in the *Back to the Future* trilogy, Doc Brown used the energy from a lightning strike to travel through time.

Electrical arcs, lightning, high voltage.

So.

’Could it be...?’

’[Is the principle behind Time Travel related to high-voltage electricity?]’

Tsk.

Jiang Ran clicked his tongue.

’This is tricky.’

If high voltage was the key, this transformer box was extremely stable. It was in the exact same state now as it had been on March 17, the day he sent the text.

So why did the message on March 17 travel to the past, while all his subsequent attempts failed?

”What on earth did we miss?”

Having personally experienced Time Travel and the resulting spacetime shift, Jiang Ran was desperate to figure out why it had happened... and especially, what made him different.

He shook his head.

”Come on, let’s go get something to eat at the cafeteria.”

...

「The next day.」

The three of them headed to class as usual.

As they passed the student club building, they noticed a crowd of students gathered in front of a bulletin board.

They got closer and saw a disciplinary notice posted on it:

NOTICE

[On the evening of March 17, Yan Rui, a student from the Film Club, used a high-power appliance in violation of school policy, causing damage to the electrical circuits. In accordance with school regulations, he has been issued a formal warning. This notice serves as a public announcement.]

”The Film Club?”

Cheng Mengxue tilted her head.

”What’s that?”

”It must be a club for enthusiasts of old-school film cameras, right? Everyone uses digital cameras or their phones to take pictures now. Film cameras are totally obsolete.”

Qin Feng replied.

”A relic of a bygone era.”

Jiang Ran stood before the bulletin board, his eyes narrowed as he stared at the date on the notice.

”I think,” he said, ”I’ve found our missing [key factor].”

??

The other two turned to look at him.

Jiang Ran gave a slight smile.

”Do you remember which club was in the room with the window behind the transformer box?”

Recalling the film canisters on the windowsill and the photos clipped to a line to dry, Cheng Mengxue had a sudden realization.

”It’s the Film Club!”

She then turned back and carefully reread the disciplinary notice.

Evening of March 17... high-power appliance... damage to electrical circuits...

”Exactly.”

Jiang Ran stepped forward.

”The evening of March 17... that’s exactly when I sent the text. And the location was right outside the window where this upperclassman was using a high-power appliance.”

He extended his index finger and tapped the disciplined student’s name.

”So, it’s highly likely...”

”The secret to the time-traveling text has to do with that high-power appliance!”