The Aegis Network is a secret, centuries-old web of supernatural operatives who handle monstrous threats by whatever means necessary. Sometimes that means killing your fellow creatures, but other times it means containing a threat and releasing it somewhere safe. Occasionally, it might involve temporarily containing a threat until a solution can be found.
Our intrepid heroes are members of the Chicago branch, a well-equipped series of homes on a cul-de-sac in one of the city's poorer neighborhoods. They benefit from being far enough from anything like a policing force that any neighbors who might have noticed odd paraphernalia or weapons being loaded into cars or trucks generally look the other way. They tend not to make enough ruckus near their home to be worth bothering. Between the occasional religious iconography and just how many people go in and out of those homes, many folks figure they're some kind of cult.
Most members of the Aegis Network are, themselves, supernatural creatures. Many joined the Aegis Network to protect humanity, and/or to keep them ignorant and therefore protect other creatures like themselves from annihilation. Humans are, after all, very good at wiping out predatory species. For some members it's about a family legacy, and for others it might be a kind of penance. A mission they support, or the only place they feel they belong.