In your opinion, what could be the most terrifying truth about them?

Assuming that the truth is so terrifying or disturbing to our society that all the governments involved would hide it for decades and decades, what’s the worst you can think of?

That our species in some way or another is doomed and the government, despite knowing it, cannot do absolutely anything? That we are a slave planet? That in reality we are alone? That the government sold us in a way horrible in exchange for their garbage? (These are just examples so you can see what I mean).