So I am putting together a one shot Call of Cthulhu game set in the modern era. Instead of doing the Delta Green thing (which I normally would) I decided to go a different direction. I made up The Hartford Society. They are a group of people dedicated to fighting the occult tide of the end times. They have all the tropes: a deceased wealthy benefactor, offices in London and New York, a large library and stuffy, officious officers.
I will have premade characters and will probably run one of the adventures from one of the Chaosium books. I find it ironic that I have 100 pounds of these damn books and hardly, if ever actually run them. I almost always run things of my own design. Go figure.