Book review: Mr Penumbra's 24-Hour Bookstore, By Robin Sloan Simultaneously an ode to musty bookshops and a call to digitisation, this is a delightful tale, swinging from a company called NewBagel through to Google's base, a hidden library and into the very future of print. It's set in silicon's world capital, San Francisco, and it will come as no surprise that the author once worked for Twitter. As our hero, Clay, explains, "Strange things are afoot at Mr Penumbra's 24-hour bookstore," an Escherian tower of shelves frequented by a series of odd customers who buy almost nothing, instead borrowing strange, coded tomes by day and by night. Clay, together with his new-media friends and a sexy programmer, sets out to unravel the mystery and, in doing so, finds himself pitted against the Fellowship of the Unbroken Spine, a sinister group of cloaked men and women that wouldn't be out of place in a Dan Brown novel. It's all very hipster, which might be annoying were it not for Sloan's lightness of touch. This is a world in which a man can own an early edition Kindle, "so uncool it's cool again," a place where Google is "developing a form of renewable energy that runs on hubris," and where a breathy description of the internet giant's headquarters is leavened by the appearance of "a tall dude with blue dreadlocks pedalling a unicycle." As Clay ventures deep into a 500-year-old puzzle, the story pushes through into the difficulties that trouble not just readers but the entire publishing industry. Where, asks Sloan, should humanity's knowledge reside: caught between covers on dusty shelves, or uncontained, accessible to all? Knowledge on paper is in chains, shackled and vulnerable; books can be burnt, life stories lost in an instant. Yet once uploaded, they fly free, flashing around the world. He draws powerful comparisons between the invention of the internet and that of the printing press, and as for the timelessness of paper and ink, as Clay says, "nothing lasts long. We all come to life and gather allies and build empires and die. But it's not quite as simple as it sounds. Our hero is in love with the tangible, with the feel of books, their bindings, their smell. When a vital book is strapped into Google's print scanner, ready for its code to be harvested, the scene has overtones of violation, perhaps even torture. Sloan is, evidently, a man conflicted. His adoration of print shines through every word, yet Mr Penumbra began life as an ebook. The guilt of a man who works in a bookshop yet only downloads free first chapters on his Kindle is the guilt so many of us feel whenever we click on Amazon. His novel confronts these issues head-on, and if the answers make for uncomfortable reading, well, they're exhilarating, too. The sheer power of computing is a constant thrill; "I love this," says one character, "my mind is not just here ... it's out there." Then there's the emotional contrast between the description of Google's "Big Box," a series of shipping containers housing much of the internet, and that of a single man, late at night, dwarfed by shadowy shelves. And if, in the end, the plot doesn't entirely satisfy - the love story is a little weak, the 500-year old mystery rather too neatly solved - this novel's ideas will linger long in the mind.