End of the world or a way to save it?

A complex tale of a new world order that still leads to the age old questions of survival, government and family. The story starts off with a bang and a stopwatch slowly ticking away until the last batch of humans is wiped out. One harebrained idea can fix it but we don't know what it entails or the cost. This is a post apocalyptic world where the elders have tried and maybe failed but have one last chance at getting it right. It seems no matter how the planet was ruined and what new society is reborn from it, kids will still be frustrated that their opinions are not heard, adults are frustrated that the kids don't respect the time and energy they have put in or their wisdom and the world keeps becoming more toxic as we go.
A post apocalyptic mystery thriller with a lot of elements and characters where it might be handy to keep a notepad close by to keep track of all the suspects.