It has immediately piqued my interest because of the unique type of content, which I'm going to explain now.
The first chapter of the book describes the Inn (which doubles as a caravanserai or modern hotel, so as to suit the current campaign type), detailing the structure and all its locations. It includes a sort of mini-game to randomly generate the features of the Inn, with the option of involving the whole group in the process, making it the core of a session: a cool idea IF you are going to use the Inn as the home base of the group, or the center of a small campaign. All the relevant, possible features of the Inn are described in detail, so they are ready to use. Note that the download also includes fully detailed maps of both the caravanserai and hotel versions of the Inn, if you don't want to generate your own.
The second chapter details all the relevant NPCs: owners, staff, and customers.
The third chapter describes the "Cascade": a tearing in time/space that turns the Inn into a multidimensional location. That's why it is an Inn Between Worlds, and the cool idea that you may use to connect various Savage Worlds settings. This chapter has random tables for locations and encounters through the Cascade, and then tables for random destinations: the cool thing here is that each destination result is briefly described, and also includes a small list of possible published setting books that may be used for that destination!
The fourth chapter is about encounters and plot hooks revolving around the Inn, including a few bizarre creatures and tables to get the party involved.
The last chapter introduces a few new Edges and Hindrances and a new Arcane Background and powers, all related to the Cascade and its effects.
As you can see, the book is designed to be plugged into any type of campaign.
The book states classics such as Hodgson's House on the Borderland and the films The Saragossa Manuscript, The Cell and Being John Malkovich, along with M. C. Escher's art, as its sources of inspiration: such works clearly contributed to the inter-dimensional features of the Inn.
One interesting feature of the book is that it makes ample use of references to the TV Tropes, instead of detailing typical story elements that may come into play in association with various places and NPCs.
As a whole, is the kind of supplement that's suited for GMs who like to cook their own campaigns and adventures, and are happy to find ready-made locations, foes, and adventure hooks. This includes dropping most of the book (and Inn, and time/space fracture) as is, in settings such as Deadlands or East Texas University, which can definitely handle all the weirdness going on; or picking just the interesting bits.
All in all, it is a very atypical supplement, with a lot going on, and one which will require some extra GM work, but full of ideas and re-usable bits. Considering the price (just $2.50 at the time of writing, which makes me forgive the very basic layout), I definitely recommend it if you think you might want to make an inn, hotel or similar establishment the centerpiece of a campaign or the setting for some adventures (even without the Cascade thing). It may serve as a Rippers Lodge for sure!