Clay finds a job at a bookstore, not just any bookstore, Mr. Penumbra’s 24-hour bookstore! It seems to be two stores in one; “There’s the more-or-less normal bookstore, which is up front, packed in tight around the desk.” “The other bookstore is stacked behind and above all that on the tall laddered shelves, and it is comprised of volumes that, as far as Google knows, don’t exist.” …”They’re not all ancient. They’re just all…unique.” These shelves go up and up seemingly forever and must be accessed by rolling ladders. He thinks of this as the “Waybacklist”. He is given three rules when he starts work; “One: You must always be here from ten p.m. to six a.m. exactly.” “Two: You may not browse, read, or otherwise inspect the shelved volumes.” Three: “You must keep precise records of all transactions. But Clay is desperate for a job and thinks, “I guess under normal circumstances this would feel like a creepy job requirement. Under the actual circumstances—lending strange books to stranger scholars in the middle of the night-it feels perfectly appropriate.” After a few days at the bookstore, Clay notices that the customers that come in for books from the Waybacklist, don’t buy them, they check them out all according to some elaborate kind of plan. The reader is also introduced to Clay’s roommates; the beautiful Ashley who owns the apartment and Mat, an artist who is intent on building some kind of model city in the living room. It is Mat who visits the bookstore and dares to open one of the books from the Waybacklist to find it contains “an undifferentiated jumble” of letters from the Roman alphabet, some kind of code. Just as they’re looking at the book, (Clay could not resist the temptation any longer) we are given a glimpse of a Waybacklist customer; Fedorov: “his beard is snowy white and the skin on his hands is papery-thin---but also probably the most clear-eyed. He seems a lot like Penumbra actually”. “Is this a book club? How do they join? Do they ever pay?” But….“Penumbra keeps his own counsel, and the message is clear: do your job, and don’t ask questions.”The next night, Neel Shah, who is Clay’s oldest friend, becomes very excited about breaking the ‘code’, and talks about how the situation resembles a ‘Rockets & Warlocks scenario’, which is the first reference to the book ‘The Dragon-Song Chronicles’ that is a favorite of both, and the author Clark Moffet.When Penumbra arrives the next morning, Clay broaches the subject of his friend checking out books from the ‘Waybacklist’. Penumbra replies that there is no money involved, the friend must enter into a contract, agree to pay close attention, and be devoted to solving the puzzle. Then Penumbra says a very strange thing to Clay, he says “The books present a puzzle” ….”but you know this, my boy, do you not?’ Wait a minute, wasn’t the second rule to the job NOT to look at the books? Penumbra’s reaction to Clay’s admission of looking at one of the books from the Waybacklist seems anticlimactic. It is another glimpse of weird; with rules that aren’t really rules; rules that are expected to be broken. Penumbra states, “there is nothing worse than an incurious clerk”. Why then did the author include the ‘rules’ at all? I think the rules add another dimension of mystery to the story, making it seem even more like a cult, a very weird cult. What is the answer to the puzzle? It will be very rewarding……Grumblegrits is a programmer known only by this name who operates between literature and code, a pirate of sorts, pirate of the written word. Thanks to Grumble’s 3D program, Clay comes up with a way to enter the books in the order they are checked out. Enter Kat, a main player in a company known as Google, where technology is unlimited and any question can be answered by the use of computers. Kat helps Clay with the help of a ‘borrowed’ log book that is scanned by a highly technological book scanner; the order of the books that are checked out creates a picture, a picture of the founder of the club/cult or group of people known as the ‘Unbroken Spine’.From that point, the reader is taken on several adventures in this quest for answers. Into the main bookstore in New York, how each member of the ‘Unbroken Spine’ files a codex vitae, capturing all they’ve learned throughout life, with the threat of having their codex burned if they break the rules of the club, the collision of old-world handwork and the automated digital age, the limitation of the Google decoders, and the simple answer that is found at the end of the book tying it up with Clay’s favorite author Clark Moffat and his series of books which also solved the mystery of the code.The answer the author provided was brilliant. I am rating this book 4 stars only because there were some parts that were questionable for me, some things that I felt weren’t necessary for the story. Then again, maybe these parts were necessary after all. Hmmm, maybe I’ll have to read this book again!! Maybe I should give it 5 stars after all because only 5 star books make it to my ‘to be read…again’ list!