One day, you were alone in your lab and someone had snuck behind you, being hostile and aggressive he/she had hit you in the head with something hard. You seemed to have went un-conscious and the mysterious person had taken you to this some sort of underground-workplace. You had no idea what was going on, but after a while, you started to begin what was happening. You were a slave for some sort of organization, working hard to obtain resources such as coal, iron, diamond, wood etc.
Many slaves like him, who were taken out of civilization, were tortured, beaten or even killed. Many were thrown in pits but you managed to survive, as you respected their orders. Even if word had got around about the project, suspects were either tortured or killed. For many years, you started to realise what was going without being noticed, he had snuck into the engineering officer's office and read a plan/blueprint.
It was a blueprint to this machine, he had read they were 2 hammers, and they were to crush and degrade the surface/crust from below, he assumed that they had slaves to gather the resources and that they built it underground so military/communities would not notice what they were going to do to the surface.
You read they were to use the hammers to do some catastrophic damage to the Earth's crust, to break and dismantle it bit by bit, gravel, stone, material, dirt would be destroyed and all living creatures would be doomed into the void. After that, you couldn't stop thinking about it, but the day after, all slaves would be killed and the machine were to be activated.
As soon as this happened, you built a compartment in your cell and gathered resources to make a cryotic bed, to preserve his body so when the place was doomed, he could wake up and survive. He was the last to be killed but suddenly, the walls started to crumble and the ground shook and the guards ditched the area, while you, being intelligent went into the bed.
Now you wake up, knowing little on what happened, a vague memory on your life, and you are trapped.