This book is basically what happens if you took Holmes and Watson, made them gay (not, you know, that they aren't already) and turned them into Ghostbusters.
The great thing about that description is you now know whether you want to be clamoring to read this ASAP or not. It is exactly what it says on the tin and what it says on the tin is a ton of fun, ridiculously well-researched while also being super campy, and I really want this on TV in the style of Miss Fisher.