As a protagonist of the game you know that the end of the world is imminent so you set out to talk to as many people as possible to save them.
Why do you think that is imminent ?
The answer of this question is in the title of this game and you will find it out along the game.
It's a game based in real facts so we can say that currently there are people in the world that are doing this right now. But not only it's being doing right now, long ago this was carried out for other people that were even willing to die for this. These are facts that you'll discover along the game.
Although you can feel a bit confused for now, you will understand it all at the end of the game we you see ... the end of the world...