When Aberations attack.
The premise is that Earth, being wrecked by humans, gave rise to some mutant humanoids, the albino, mostly nocturnal, ferociously strong and blood thirsty Abbies. (aberants? aboriginals?) The Abbies build nothing. They seek to destroy anything built.
One scientist recruited or kidnapped people, put them into hibernation for two thousand years, and built an impregnable valley fortress to shelter them from the Abbies.
It's the engineering and the economy of the place that tick me off. How could you make a place that would tend itself for two thousand years, especially against humans before they were destroyed? How could you store that much food and power?
And how would humans not efficiently wipe out the Abbies, small in number at first, as they proved themselves able to wipe out every large beast they set their mind to?
The mystery kills the reasoning.
If it is so darn dangerous outside, you tell everyone up front and demonstrate obviously so that they are compliant with rules and work harder to support the threat.
And when there are only a few known humans left, you don’t kill them unless there is literally no other choice.
Playing up the drama is at the expense of the logic.
I've been saying the same about zombies for a while now. The real fighting would take place between heavily armed rednecks over who gets to kill the last dozen or so remaining zombies, after the rednecks go on a two week "hunting" spree that pretty much ends the zombie menace (and leaves behind one h3ll of a stinking mess).
When Aberations attack.