BookBrowse Reviews Mr. Penumbra's 24-Hour Bookstore: The mystery at the heart of Mr. Penumbra's 24-Hour Bookstore takes Clay from the headquarters of Google to a subterranean library in NYC, from fifteenth-century technologies to the most sophisticated computing networks of the twenty-first century.

Mr. Penumbra's 24-Hour Bookstore is a novel whose own history uncannily echoes its themes. The original genesis of Sloan's debut novel was as a self-published ebook short story, which then, following its overwhelming success in that form, found its way to a print publisher and a new life as a traditionally published, full-length novel. Likewise, the plot and themes of Sloan's novel continuously - and vigorously - cross the boundaries between old and new technologies, between traditional knowledge and new ways of thinking, between a possibly irrelevant past and a still undefined future.

The central figure in this drama is Clay Jannon, a twenty-something graphic designer who has been the victim, on more than one occasion, of the Great Recession. To make ends meet, he finds himself working as the night clerk at the eponymous bookstore, which is really two bookstores in...