"Sir! Sir! They've found us! We have to evacuate!" A breathless young man in tattered military fatigues burst into the lab.
The elderly man sitting at the primary control console shook his head, a manic gleam in his eyes. "No! We must proceed! We are almost done! If we leave now we will lose everything we have worked for!" He pressed a button on the console and his voice was projected from loudspeakers throughout the underground facility. "We are out of time! We are launching immediately! Everyone to their positions! Humanity shall rise triumphant!"
The facility burst into wild activity like a kicked anthill. Worn looking soldiers took up defensive positions with a grim resolve, while people in lab coats scurried from room to room desperately checking equipment and calculations. Through the lab's window the elderly man watched as the last hope for mankind was strapped securely in the heart of the Temporal Displacement Engine. This was the third such engine he had been forced to build, and he didn't have the time or resources to build a fourth.
The first Engine had been constructed to prove his mathematical solutions to several temporal equations that had stumped mankind for over a hundred years. Not long after his volunteer pilot had returned with proof he and the rest of the world learned not only that they weren't alone in the universe, but their fellows took great offense at any attempts to manipulate temporal energies. Colonies across the solar system started to go dark without a word, then a few weeks after losing contact with the last known offplanet human enclave, massive ships simply materialized out of nothing in orbit and began bombarding the Earth mercilessly. The first machine was destroyed by this unexpected assault.
His second Engine was built after several months of guerilla warfare as the aliens landed ground troops and began rooting out the few remaining survivors. They worked tirelessly in a hidden facility much like this one so they could send someone back to change the course of time and prevent the invasion. He failed to account for the temporal distortion caused by sending someone from the future into the past with the intent to change everything. The moment the pilot tried the removal of the need to send him back in the first place removed the changes he made, and the shockwaves twisted both the machine and the pilot into an unrecognizable lump. It also rang throughout the continuum like a gong, and they were barely able to escape the immediate retribution of the invaders and make it to their current facility.
This Engine was different than the other two had been. Using captured alien technology that had been acquired at a great cost in lives they had discovered a way to shield the internal cabin from the temporal energies, effectively severing it from the timestream entirely. The A.I. built into the cabin would activate the moment the shielding activated and it would create its pilot from the genetic material it was provided with, the Engine should be able to spend as much time as it needed outside the timestream to allow its pilot to grow to a suitable age. Cybernetic enhancement and intensive digital training systems would ensure that the pilot possessed everything they needed to succeed in their mission, and the fact that their entire existence had been created outside the natural timeline should prevent them from being affected by any temporal shockwaves or distortion caused by their presence in the past.
It was the greatest gamble in the history of the human race, and now their hand was being forced. "Activating T.D.E. Temporal energies are building according to projections, all systems nominal. Five minutes to launch." The facility shuddered suddenly as something impacted the surface above them.
"Troop transport just landed! Hold them off! We are the last hope for humanity!" The shout carried through the tunnels, followed by the chattering of automatic rifles. The lights flickered. "Shit! Generator one just went down! Protect the rest of them! We can't lost another before the Engine is self sustaining!" Screams and roars echoed chaotically through the facility as the defenses were overrun. They only just barely managed to succeed, losing a second generator only seconds after the Engine came fully online and began supporting itself on pure temporal energy.
The elderly scientist that had inadvertently started this apocalypse stared through the lab window as crackling golden energy encased the Engine. As the final seconds ticked down something impacted the door violently. "Farewell and godspeed." He said solemnly as a large four armed alien smashed through the door on its second strike. It tossed something inside before ducking back behind the wall, and the last thing the man saw was a brilliant blue flare of energy that shattered the window and flooded out into the Engine room.