Other settings have long-dead alien gods buried deep beneath the earth, ancient layers of fossilised vampires, the residual sludge of entire eras in which everything was magic, an entire Underdark filled with magical beings. Necrocarcerus doesn't. Instead, what it has is a megacorporation that goes to those places, throws those rotting gods and insane liches into threshers, and then extracts whatever valuable substances, divine energies, negative planar energy, or plain old hydrocarbons are found in them. This is where you come in.
PetroNec, the Necrocarceran gas and oil corporation, is an old hand at this dirty business, and it's happy to hire adventurers to jump through a portal into one of the Living Worlds, poke around in the tome of some ancient god-king, trigger all the traps, slay all the skeletal tomb guardians, and then show a lode of forty cubic metres of enchanted bone and ensorcelled metal (2.5% finders' fee) with a gangue and overburden of some hundred thousand cubic metres of useless gold, silver, assorted pieces of granite, and dead adventurer.
Get in, find the dead god or the sea of mana-tar, kill whatever could wreck an extraction pipe stuck into it, get back to the portal. Everyone wins. The people who need liquefied undead for coolant get their liquefied undead coolant. The Council of Ninety-Nine sees their share price go up. You (probably) get paid a hefty sum of obols, if you survive. And then it's onto the next portal, the next claim, and so on until you either manage to retire or you end up a smear of hyle and ichor in some blighted chasm, gnawed on by ancient imprisoned horrors. Not that this will stop the patachemical industry. Nothing ever does.