This product is a result of a major Kickstarter effort launched back in November (and concluding on 12 December) of 2012. It's been a long time coming, but is well worth the wait thus far. There are three basic "books" in the package; a Keepers' Guide, an Investigators' Guide, and a package of handouts for the included scenarios. Kickstarter Backers should note that the adventures do NOT include the forthcoming "Curse of Nineveh" package promised as part of the Kickstarter and are instead a series of stand-alone scenarios for use in London and it's immediate environs.
Like all Cthulhu Britannica products, this one does a superb job of helping players get into the setting being provided, but this one goes a good step further than any of the previous ones have; perhaps fitting considering that we are discussing "the Smoke," the largest city in the world at the time. There is generally excellent discussion of the city overall, most of the major districts, and many of the nuances that make each district unique within Greater London. In addition there is a ton of background information on the 1920s in England and London particularly (train stations and their various connections are amazingly important...and thoroughly discussed) in the book along with lots of tid-bits of local color and history which will inspire even the most casual leader to hit the internet to find out more. Speaking as an American player, one of the more jarring things for me (as it would have no doubt been had I been alive in the 1920s and ventured into London) is the lack of Prohibition, but that alone may provide an extra incentive for your wealthier (dare I say it -- more dilletantish) characters to go to London in the first place! There are many detailed maps of various locales within London, including parks, zoos, museums and so on, along with quite a few period photographs that will help the players visualize both the location and the era. The attention to detail on this one has been simply fantastic, and while it still can't come close to covering everything there is to know about London, this is far and away the best effort yet. Comparing this to the old "London Guidebook" is like comparing Shakespeare to Gershwin -- both are great in their particular areas, but in the big scheme of things, there is just no comparison. I suspect when we are holding the finally completed package together with all the extra goodies we helped fund through the Kickstarter, we will have the last word in 1920s London at our fingertips. Cubicle 7 has done another fantastic job thus far, and I can hardly wait to get the hard copy in my hot little hands!
Overall the quality of the reproduction on this one is unsurpassed -- not surprising when you consider it was probably a copy (more or less) of the files to be sent to the printer, as opposed to a scan of an already extant product. Purchasers of this item will definitely not regret picking it up!
[5 of 5 Stars!]