“CC?” Lin Xian blinked at the familiar face in front of him. “What are you doing here?”
This was incredible. It had to be more than just a coincidence. He had been thinking about her, and now here she was.
“I’ve been waiting for you,” CC replied with a soft huff. “Didn’t we make a promise in those fragments of memory? That I’d wait for you here, in the most obvious place in the Donghai area, on this exact day?”
She frowned, clearly annoyed. “Don’t tell me you forgot.”
“Of course I didn’t forget,” Lin Xian said, shrugging. “But usually, on the first day in a new world, I need time to get a feel for its reality. Plus, today, well... I ran into some trouble right when I got here. Had to escape through a sewer.”
He gave her a faint smile. “You have to understand, for you, this world is one you’ve been in for twenty years. For me, I’ve been here less than twelve hours.”
He glanced up at the museum ceiling. “So... this museum is the most obvious place in Donghai City?”
CC nodded. “I think so. It’s right in the center of Donghai City. It’s iconic, easy to spot. I’ve been up on the museum rooftop since noon, waiting for you until nightfall without a sign of you.”
“Then, about an hour ago, the manhole covers all over Donghai City started banging open. Right after that, there was an explosion here at the museum. I knew it had to be you making trouble, so I came in right away.”
Lin Xian nodded. Today had been his first time entering this dream, and everything had happened so quickly. He had been taken to Sin City by Xu Yi Yi soon after arriving, and he hadn’t had time to find CC.
There was no way he could forget their promise. When the fifth dream ended, he had danced with CC to create a perfect memory for her. During the seventh dream, he had taken CC to find Li Ning Ning and watch the bonfire.
This time, he really had to thank Big Cat Face and the C4 bomb. With how chaotic Donghai City was now, people were running around playing hide and seek and chasing after androids. Without that explosion, CC probably wouldn’t have found him.
Seeing CC suddenly appear, Xu Yi Yi tightened her grip on her weapon, taking up a defensive stance. Meanwhile, Big Cat Face struggled to pull off his Rhine Cat mask, which had gotten stuck on his ear.
CC watched the amusing scene and tilted her head. “Did I... come at a bad time?”
“No,” Lin Xian shook his head, a smile forming. “You came at just the right time!”
He turned around, pointing at the titanium alloy door and the lock beside it. “Quick, take a look. See if you can crack it.”
He stepped aside, gently lowering Xu Yi Yi’s dagger. “No need to worry, she’s a friend—a password expert.”
CC walked past them, giving Xu Yi Yi a quick glance before looking up at Lin Xian. “You really are popular with the girls, aren’t you? Every world you go to, it’s always a different type of girl hanging around you.”
“Stop talking nonsense!” Xu Yi Yi lowered her weapon but remained wary of CC. She stood protectively in front of Lin Xian as if shielding her ‘little brother’ from harm. “This is my little bro! I’m the one looking out for him!”
CC paused, glancing curiously at the young girl before her. She couldn’t quite understand how this unpredictable Lin Xian had ended up as a ‘little brother’ to someone like her. She narrowed her eyes at Lin Xian. “What kind of game are you playing now?”
“Come on, focus on cracking the lock,” Lin Xian urged, glancing at his watch. It read 11:17 PM. “We don’t have much time left. Only an hour and a half.”
He added, “According to Godfather Gao Wen, there’s a time-space particle in this exhibition hall. We need to steal it as soon as possible.”
CC walked over to the lock, examining it closely. “This isn’t an ordinary password lock. There’s no actual password. To open the door, you’d need proper verification.”
“So what do we do?” Big Cat Face finally managed to pull off his mask and stepped closer. “If there’s no password, does that mean we can’t crack it?”
“Of course not,” CC shook her head. She pulled out a small computer from her bag and used Xu Yi Yi’s dagger to pry open the lock’s casing. “No password doesn’t mean there’s no key. Verification information, whether it’s a card, facial recognition, or a fingerprint scan, is just a type of password. The difference is, a normal password is a combination of numbers and letters, but this one is a bit more complicated.”
“But as long as it’s a password, it can be cracked. For mechanical locks, there’s brute force; for electronic ones, there’s address-searching. Given enough time, theoretically, no password is unbreakable.”
CC connected the lock’s system to her small computer with a data cable, her fingers moving quickly over the keys. Big Cat Face leaned in curiously, watching the screen flicker with streams of data.
“Looks like having a password expert really comes in handy,” he muttered.
Ten minutes later, there was a clear clicking sound. The titanium alloy door opened with a soft sigh.
“Amazing...” Xu Yi Yi looked at CC, awestruck. Her wariness melted into admiration. “You’re incredible!”
“Not really.” CC shrugged off the compliment, putting away her computer and leading the group inside.
The hall was a special exhibition area, filled with artifacts that looked extremely valuable. From a distance, Lin Xian spotted a glowing blue orb, suspended in midair inside a display case.
“There it is,” he said, jogging over and peering inside.
A time-space particle.
It really was a time-space particle.
But...
“No energy?” Lin Xian noticed something was off. The blue orb was trapped inside a transparent, basketball-sized container. It seemed calm, dormant even. Despite the bright blue glow it gave off, there was no active charge—just countless fine blue threads swaying lazily on its surface, like branches in a breeze.
Lin Xian knew time-space particles well, and it only took one look for him to realize this was an energy-depleted time-space particle. And not even an entangled one—just an ordinary particle.
This was exactly what he had feared but hadn’t said aloud to Gao Wen:
Without using a special entangled time-space particle, even if someone travels back in time, they would be unable to alter history due to the constraints of the laws of time.
Gao Wen and Chen He Ping hadn’t grasped this. They were still stuck in theoretical speculation, without enough experimental data to understand the laws of time.
But now, it didn’t matter anymore. This was just an ordinary time-space particle—and an energy-depleted one at that. Even if they took it back, it wouldn’t power the time machine.
“Ughhh.” Lin Xian let out a sigh, not sure how he would face Gao Wen when they returned. Gao Wen was probably expecting that, with the time-space particle, humanity could be saved, that the future could change. But this depleted particle shattered Gao Wen and Chen He Ping’s lifelong dreams.
“Well, let’s take it back anyway.” Lin Xian shattered the glass of the display and took out the transparent container holding the time-space particle. Together with Big Cat Face, Xu Yi Yi, and CC, they left according to their original plan.
In Sin City, even in the dead of night, the place was bustling. People were celebrating their successful operation. But deep in the underground lab, Lin Xian, CC, and Gao Wen were all expressionless.
Gao Wen let out a long breath through his nose. He looked up from his workstation, his face filled with despair. “This time-space particle... it has no energy.”
“Yes,” Lin Xian nodded. “I’m really sorry, Gao Wen. I wish I had something comforting to say, but to be honest, even if this particle was fully charged, it’s just an ordinary time-space particle. Even if a traveler used it, they wouldn’t be able to alter history because of the time laws.”
Lin Xian explained the relevant time laws in simple terms to Gao Wen, who listened intently, deep in thought. As smart as he was, it didn’t take him long to understand.
“I see,” Gao Wen sighed deeply. “The laws of time are indeed incredibly intricate. Chen He Ping and I never imagined it would be this way... Time-space particles are even more complicated than we thought.”
Gao Wen then wrote on the board—
“Astatine-339.”
“Astatine... 339?” Lin Xian blinked. “Astatine doesn’t exist on Earth?”
“I remember my chemistry teacher saying that every element in the universe exists on Earth. The periodic table has 118 elements.”
“Ninety-four of those elements are natural, found on Earth, and the rest—from Element 95 to 118—can all be synthesized in labs.”
“Sure, they’re mostly superheavy, radioactive elements that only last a few milliseconds before decaying into something else. But even if it’s just for milliseconds, those elements technically exist on Earth, right? And if they exist here, they should exist elsewhere in the universe too, with the same half-life. There shouldn’t be any element out there that doesn’t exist here.”
“If there’s an unknown element out there, it’s just irresponsible science fiction. The atomic structure of the universe is fixed—118 protons max—so there can’t be more than 118 elements.”
Lin Xian recalled reading reports about how laboratories worldwide, including those with particle accelerators, had tried—and failed—to create Element 119 by adding an extra proton to the nucleus.
His chemistry teacher had said that every element in the universe could be found on Earth. Lin Xian had found it surprising at the time, even arrogant, but his later research confirmed it—whether he liked it or not.
And astatine—Lin Xian was pretty sure it was a radioactive element.
The number after it—it must be the isotope of astatine.
Wait...?
Lin Xian thought back to his chemistry lessons.
Astatine-339?
Impossible!
Astatine’s atomic number is 85. How could there be an Astatine-339 isotope? It made no sense!
“What’s with Astatine-339?” Lin Xian asked.
“This isotope—it’s not that it doesn’t exist on Earth. It shouldn’t exist anywhere in this universe.”
“Exactly,” Gao Wen said, nodding approvingly. “Looks like your fundamentals are solid.”
He then wrote down a range on the board: Astatine-191 to Astatine-229, and continued:
“According to current scientific understanding, astatine has 39 isotopes. The most stable one is Astatine-210, with a half-life of 8.1 hours. The least stable is Astatine-213, with a half-life of just 125 nanoseconds. After alpha decay, it becomes Bismuth-209, which has a long lifespan.”
“These 39 isotopes should cover all possible forms of astatine. There shouldn’t be any others in the universe. But...”
Gao Wen’s expression grew serious as he looked at Lin Xian.
“What if Astatine-339, just like time-space particles, doesn’t belong to our universe?”
Lin Xian’s eyes widened.
“You mean this Astatine-339 comes from another dimension? Another universe?”
Considering the existence of time rifts, particles that could cross universes, and time travelers from other dimensions, Gao Wen’s idea wasn’t impossible.
But then...
Lin Xian turned to the massive time machine.
“Then how did you manage to build this time machine?”
Gao Wen turned back to the board and wrote another date:
“March 27, 2077”
Seeing that date, Lin Xian paused.
That date... it was the one Galileo had mentioned when Einstein asked about humanity’s next major astronomical breakthrough—at yesterday’s Genius Club gathering!
After writing it, Gao Wen turned and spoke slowly.
“March 27, 2077. It’s a landmark day in human astronomical history. On that day, there was a revolutionary discovery—a breakthrough that changed everything.”
“Astronomers, using their telescopes, spotted a distant comet—one traveling from the edge of the solar system toward Earth.”
“Nothing unusual about that—comets are common. But this one was different—its trajectory, speed, and spectral signature were unlike anything previously observed.”
“I won’t bore you with the complex details. But from its spectral analysis, astronomers deduced that this comet carried something alien—not from our universe, not from our time.”
“But the comet wouldn’t reach Earth for over a hundred years. All people could do was wait.”
“Then, in 2234, it finally entered the solar system—heading straight for Earth with an incorrect gravitational coefficient. Thankfully, nations had prepared, and nuclear missiles intercepted it before it hit the atmosphere. Its fragments orbited Earth for years, slowly falling and raining down.”
“And from that point on, Earth became host to several unexplainable isotopes—including Astatine-339.”
Lin Xian was still thinking about Galileo’s question to Einstein, but snapped back to reality as Gao Wen finished speaking.
“I see,” Lin Xian said. “So, the challenge isn’t the technology—it’s when Astatine-339 will reach Earth.”
“According to you, that comet—from another universe, another dimension—will only arrive in 2234, bringing Astatine-339 with it. So that means...”
“Exactly,” Gao Wen said, nodding solemnly, regret evident in his voice. “Because the comet’s arrival date is fixed, the earliest time a time machine can be built and used is also fixed.”
“If you’re truly from 2024, and that’s the only time you can return to... then, as I said before, the soonest you’ll be able to use a time machine is—”
“Two hundred years from now—the year 2234!”