Hellsalem's Lot, the city of equality, truth, charity. A city where humans and alterbeings alike live in harmony.
If that were entirely true, the organization that's goes by the name of "Libra" would not exist, and New York City would still be where it always was.
A few years ago, an event now known as the Great Collapse occurred in the Big Apple, causing massive destruction to the city, as well as to what was under it. Why it happened and how it happened is still a mystery...
As a result of this catastrophe, what was beneath our surface rose up to it. The Alterworld was now apart of our world. The population in Hellsalem's Lot became 50% monster, 20% unknown and weird, and humans make up the remaining 25%, having about half that have their own strange secrets.
Don't worry about that last 5%.
That's where Libra comes in.