To move faster than light.

Like thoughts.

The tangible form of the mind.

A physical particle.

A reality within four-momentum space.

It wasn't supposed to exist.

"I thought space isn't a vacuum," Luhan asked, unabashedly confused at the discussion before him. This was something he had to learn, they said. He had to understand this, because he was going alone. There would be no way of contacting him once he goes through, and if something bad happens, it was likely he might never find his way back.

This might be a one-way trip.

"It is not a perfect vacuum," Dr. Feng answered. He smiled, seemingly pleased that Luhan knew to ask that question. Many people would have just accepted and assumed space was a vacuum in such an intense explanation of time travel. This boy is a good choice for this. He is smart; he has a good head on his shoulders.

"Space, because it is so big, is mostly empty. The particles floating through it are so far apart and so strongly attracted to the large masses near them that there is mostly nothing left in between these large clusters. So you see, the density and pressure in these in-between spaces are very low that they can be quantifiably described as a vacuum."

Luhan squinted. He understood very little but it can't be helped. He wished he listened more closely to his high school Physics teacher though he doubted it would matter. Dr. Feng appeared to be satisfied enough to move on to the next lesson.

"... this is why we'll have to get you up there--"

"Woah, up there??" Luhan couldn't stop himself. The doctor blinked at his shocked face.

"Well, yes. We are at a space station, aren't we?"

"I'm going to outer space?!" Luhan's voice rose a little, the color on his face slowly disappearing.

"Oh my boy, it's okay. Gone are the days when an astronaut needs many years of training to even enter a flight simulation. You will need only a few months."

Luhan felt his stomach turn uncomfortably, but he knew in his heart he was determined to do this. A few months... He thought of the boy on the other side. That last time was the last transmission he could make before they needed his radio. He didn't want to let them take it apart but it was the only way they could study the events properly. By the time the doctor finished his explanation, Luhan's mind was already set on shortening his training period as much as he can. He was waiting.

Then there was the matter of his parents.

"You can't go," Luhan's mother cried, her voice faltering. "If you never come back..."

"Hush," his father whispered gently, holding her by the shoulders, tight and close. He turned to Luhan. "We can't make your decisions for you, son. We know...you know... this is important for many people. But for us, the only important thing is what you want."

Luhan tried not to cry. He wanted to show his parents that he was determined. That he wasn't scared. The truth is, no matter how badly he wanted to take this leap, he was still so afraid. 

"Of course I'll... I'll come back, Mom," Luhan managed. His mother sobbed into her husband's pique polo. She quickly ironed the place where she'd sobbed with her hand and looked at Luhan intently.

"I know. I know you will, Lu Han."

Luhan was dressed in a dark blue suit with a skinny satin white tie. He walked along the carpeted aisle of the executive office with Dr. Feng and his assistant, Zhang Yi. They were briefing him on the questions that might come up during the press conference that was about to take place. Luhan thumbed at his collar nervously. He thought it was all going to be low key and secret. Apparently, information had leaked out in the middle of his training. It was a miracle no one knew of his identity until a few moments from now, when he will be introduced to the world.

The conference room was large and oblongated, more than a dozen packs of camera equipment set up on a lowered floor while media representatives from almost every country were seated on elevated circular platforms facing a long desk. On the desk were four microphones and the name of the space station. Behind the desk was a step and repeat wall of the world's foremost space exploration organizations--all of which Luhan was now familiar with as each one had provided him with a mentor in the different areas of his training--health and endurance as well as geoscience and physics.  

Zhang Yi pointed after Dr. Feng took his seat on the second position, Yixing to his right on the third. The two seats on the edge were occupied by the station chief and flight project head. The moment he walked in, a ceaseless barrage of flashes greeted him, the media settling into a frenzy. Dr. Feng gestured for some quiet before he and the other two began to recite the media brief that had been earlier prepared. Luhan kept quiet, trying hard not to blink too much from all the cameras. He saw himself on one of the monitors and looked away. 

"And this is the mission's first participant, Lu Han."

Luhan was startled upon hearing his name. He looked beside him where Dr. Feng was smiling encouragingly. He was supposed to greet the press. Luhan cleared his throat and forced himself not to stutter.

"Hi. My name is Luhan, from Beijing, China."

The throng of reporters burst into calls for questions and raised hands. Luhan wasn't sure what to do but luckily Dr. Feng was leading the panel. The first reporter was a guy from BBC. Luhan only vaguely understood his question because of the British accent. Dr. Feng translated for him.

"Both your age and lack of experience in this field seems unprecedented, if not underhanded. Did you ever consider letting someone else take your position? "

Dr. Feng peered at Luhan from the corner of his eye, Luhan saw. This felt like a test to him.

"This is... something that means a lot to me, having had the experience and now understanding what the experience really is. I don't think I'll be able to live without regret if I don't do this. The truth is," Luhan paused. He turned his head to look at Dr. Feng, but the doctor's eyes were now gazing forward, not at him. "The truth is, it feels as though I was chosen, and that the position was mine to bear from the moment I bought the radio."

There was a lump in Luhan's throat throughout that sentence. He just wanted this to be over. Dr. Feng pointed at the next reporter.

"They said you made contact with a person from the past. Is this true? How do you think this affects us now, here in the future?"

This time Dr. Feng spoke before the question was translated to Luhan.

"We cannot answer that question for now. Our instruments clearly indicate a tachyon disturbance connected with Lu Han, and that is what the proof will be for now."

When Luhan heard the translation, he wondered why Dr. Feng didn't let him answer. To him, that contact was fact and it was after all his sole reason for being here. He opened his mouth to speak but Dr. Feng pressed on his hand firmly under the table. He leaned over and whispered to Luhan.

"It is not the time for them to know, and it is irrelevant to the purposes of this mission-- For the media, Luhan. I know that it is personal for you, so it is even more important that that incident be kept private only."

Luhan nodded in reply. After that, most of the questions were trivial--his age, his hobbies, his training process. Luhan half-trudged through the conference, relying heavily on Dr. Feng's lead. The moment they finished, Luhan let out a big sigh of relief and loosened his tie.

"I thought it would never end," said Luhan, slumping in his chair back at the housing quarters.

"You did good," Dr. Feng gave him a pat on the back just as Zhang Yi entered the room with a pile of papers and some refreshments. "Today you may rest, Luhan. The flight is in 3 days. There is a lot more to be done."

After Dr. Feng dismissed him, Luhan found himself wandering out onto the upper deck. It was freezing. He walked across the deck to the laboratory entrance, all the while looking up at the sky. Space seemed so far, so infinite to him. Did he really have to go that far just to reach him? 

I wonder what he's doing now...

Luhan went inside several instrument areas, reaching his destination at the very last door. He scanned his ID at the automated security lock. It opened with a draft of air. His heart jumped as he walked in, the familiar hum of static and sight of his radio in front of him. It was encased in a thick bullet proof glass box. He reached out, touching the glass. He missed it. He missed the dreams. They stopped when he stopped using the radio. Dr. Feng said it was because of his physical location. 

He pressed his palm to the glass. His breathing appeared as white condensate on the glass.

"Almost there."

The shuttle Luhan is in was bound for a small void space at the edge of the Kármán line, between the Earth and the Moon. Despite the advances made in human spaceflight technology in the last hundred years, even in 2098 Mars was the farthest the human carrier shuttle could go within safety boundaries. The space they were aiming for still of course had plasma and radiation, being within a tight system, but there was a particular EM current coordinate that Dr. Feng and the other scientists called the Tachyon point. They predicted that it is a promising spacetime point because of the low atmospheric density and pressure as well as a distinct amount of observed Cherenkov radiation that appeared at the same time as the signals from Beijing and Seoul. 

Cherenkov, Luhan remembered the discussion a few weeks ago. Everything still felt too much for him to comprehend, and here he was sitting in a shuttle cockpit. 

"Do not worry, we will be in contact at all times while you are in the shuttle. The spacecraft will be manned via computer here at the base. All you need to do is keep calm and remember the instructions we practiced during the simulation."

Luhan swallowed hard. There was a small ache in his stomach he recognized as hunger but he doesn't feel like eating at all, even though he hasn't eaten in the last 24 hours as per regulation for spaceflight. His mind was strangely blank, probably from nerves. All he could manage was a small nod.

The shuttle began to vibrate slightly violently. Luhan gripped the armrest. In his ear monitor he could hear someone counting down, a series of calls and affirmations as the seconds dwindled to zero. 

Then, blast off.

//...