From the back of the booklet:
You are a cabal of adepts and avatars, minor checkers in the Occult Underground. You get word from a mutual friend of yours that someone very important to keeping the peace in your city has gone missing. Sure, people go missing all the time, but this woman Maria is a Van Helsing. If she's dropped off the radar, who knows what kind of mess she's gotten herself into?
Quickstart scenario for Free RPG Day 2018.