The skies swarmed with the prodigal sons and daughters, vengeful angels from the past. Those that had sent them panicked, fearful of the mess their ancestors had created.
Chaos. Without a single act of aggression.
And those who returned realised that they were so far above the planet bound as to be another species. Above them. In so many ways. It wasn't sorrow, or regret, or mercy. Just indifference.
The old world was gloomy, dank, depressing.
So they left. Again.