There's a lot of very useful information on London specifically and England in general in this Call of Cthulhu supplement. I found the historic information interesting, and I think it will help me make a game more immersive if I get around to running it. However, I did find that the book tended to lean into the sort of Victorian penny dreadful kind of setting, in much the same way Chaosium's 1920s supplements tend to lean more toward a pulpy vibe. There seems to be less interest in Cosmic Horror, existential dread, and mind shattering alienation, and more on monster hunting and ghost chasing. Even the two adventures feel more like something out of Bram Stoker than Lovecraft. Still, I think this will be a big help in future games I might set in the era.
Solid supplement for Call of Cthulhu adventure in the Victorian period, revised to dial back the superfluous and genre-inappropriate Sherlock Holmes stuff in previous editions. Full review: https://refereeingandreflection.wordp...
This book contains all the details you need to know for Call of Cthulhu in victorian London plus a long scenario, in which a well-known fictional detective helps in solving the case...