"You will serve in silence", which accompanies the Elder ripping your tongue out and eating it in front of you.
How about seeing dead human bodies hung up just like any other type of animal meat?
The City Fathers of New York, hideously ancient immortal cannibals who secretly rule the city, and have done so since New York was founded during the colonial era. While not particularly weak, they still age physically, meaning they look more like sexless ghouls than the humans they once were. And worse, it's implied every great city of the world have similar covens of monsters in charge.
They, in turn, are just servants to the "Father of Fathers", a horrific Eldritch Abomination living beneath New York, who is the true source of their immortality and the vague powers that keeps the city great. Kaufman only gets a glimpse of a teeming mass of... something hiding in the darkness of the underground tunnels, and it's enough to almost drive him insane.
There is only one Butcher at a time, but obviously one man couldn't possibly hide all of this on his own, right? As it turns out, the city municipal workers are in on it, and it's impled that so is the rest of the government, making sure all evidence of the Butchers work and the City Fathers feast is gone by the time the subway trains run again.
The scene where Kaufman wakes up on the train in the late night hours, only to hear strange sounds coming from the next cabin - it's the sound of the Butcher preparing his victims.
Film Examples:
Your everyday life is just a cover for a horrible, horrible secret. You want to be a hero? Good luck: Your life will be turned upside down to manipulate you and exploit your dark tendencies to turn you into a monster who kills random people and feeds them to freakish creatures that live underground. Also, try riding a late night subway after watching this movie and not being... jumpy.
