Warning

Matthew sat at his desk, head cradled in his hands, pounding not for the first time. Mathematical equations rushed through his brain, threatening to overtake his consciousness and turn him into a human calculator. There were too many variables to calculate, too many possibilities he had to account for. And that was merely in the theoretical stages of the experiment. There was still the tests to be run to determine what materials would actually be usable in order for his creation to be successful, and then the full construction. And then there would be the tests to see if that construction would be successful when constructed.

There was a reason that time travel had not been constructed. The amount of energy required to fuel a tear in the space-time continuum was enormous, and not even a thousand nuclear power plants would be enough to sustain it long enough to make a single leap, much less a return trip. It would need to be enough to be accessed remotely as well if one wished to be able to return to the time they had originally leaped from. And this was all assuming that the tear one made in order to travel would be clean - like metal, any stress fractures or cracks it created could potentially lead to the very structure of time shattering, destabilizing the very existence of the universe as they knew it.

Theoretically, prodding at the fabric of reality like that in the first place would be a make or break deal. Too many failed tests would lead to the same results as finding a sketchy success. But there was a time and a place for risk, and with all of time and every place at his disposal, he was sure he could find one as an excuse for his experiments. But it would take time to complete. Matthew could only work for so long at a time before the mental strain was too much and threatened to shut him down.

He stood from his chair, intending to go upstairs and into the kitchen to make himself a pot of tea, when there was a sound like a sonic boom barely a dozen feet behind him, nearly tearing apart his eardrums and knocking him to his knees. He looked back to see the air itself torn apart, a black void floating in the air, and an aged version of himself stumbling out of it.

"It worked!" he exclaimed, though the pain in his ears meant that he could barely hear his own voice. He was looking at himself from the future. His experiment would be successful. He would invent time travel.

But the future him was trying to speak. He could see his own lips moving, but he could not make out the words. His ears were ringing - they felt wet. The future him looked... angry? Upset? He wasn't sure. But he kept pointing at himself, and back at the space where he was planning to build. Did he want him to build elsewhere? In that spot? His brain was too tired to comprehend.

And then it was as though there was a heavy wind blowing towards to void, and the future him was having trouble standing his ground. His feet left the earth, and he tumbled back into it, and then they were both gone.

Matthew's ears were still ringing, pain tearing through his head. He needed his tea. That was the only thing that could help him focus in that moment.