This episode takes place on September 28, 1980 and in 1996.
As Xanatos has allowed the clan back to their ancestral home, they are now safe from the bigotry of humans who think they're mindless beasts.
Robin and John make the bad call of fighting the Manhattan Clan instead of going after Demona, the real threat who almost succeeded; all because they were too dense to see the gargoyles were trying to stop her.
It's unknown if Thailog was backing Demona's plan; considering he was the materialist views of Xanatos and would be very annoyed if the human luxuries vanished.
Irony: John becomes a mirror of Demona. Both embrace a hatred for the other's species just to avoid accepting they are responsible for their own misery and guilt.