Picture the adventuring party of most old-school games. A band of thugs, occultists, criminals, weirdos and outcasts who, rather than settle into normal society, risk everything exploring the dark, dangerous places of the world. Perhaps they will become rich and powerful, perhaps they die unceremoniously.
Keep this same adventuring party, and picture their equivalent in the modern day. A world with police, the internet, chain stores... The same band of thugs, occultists, criminals, weirdos and outcasts drift into the underworlds of organised crime and the esoteric.
This, then, is the premise of Esoteric Enterprises: the occult exists in a dangerous black market, where organised criminals traffic in magical grimoires and relics alongside narcotics and weapons. Hidden from the public eye, various gangs, cults and covens struggle for influence and resources in the dark tunnels beneath every city. And beneath that, stranger things lurk; inhuman creatures turn their cold gaze on the mortals who intrude on their subterranean realm.