Mr. Penumbra’s 24-Hour Bookstore by Robin Sloan

January 21, 2013

Plot summary (from the publisher): The Great Recession has shuffled Clay Jannon out of his life as a San Francisco Web-design drone—and serendipity, sheer curiosity, and the ability to climb a ladder like a monkey has landed him a new gig working the night shift at Mr. Penumbra’s 24-Hour Bookstore. But after just a few days on the job, Clay begins to realize that this store is even more curious than the name suggests. There are only a few customers, but they come in repeatedly and never seem to actually buy anything, instead “checking out” impossibly obscure volumes from strange corners of the store, all according to some elaborate, long-standing arrangement with the gnomic Mr. Penumbra. The store must be a front for something larger, Clay concludes, and soon he’s embarked on a complex analysis of the customers’ behavior and roped his friends into helping to figure out just what’s going on. But once they bring their findings to Mr. Penumbra, it turns out the secrets extend far outside the walls of the bookstore.

With irresistible brio and dazzling intelligence, Robin Sloan has crafted a literary adventure story for the twenty-first century, evoking both the fairy-tale charm of Haruki Murakami and the enthusiastic novel-of-ideas wizardry of Neal Stephenson or a young Umberto Eco, but with a unique and feisty sensibility that’s rare to the world of literary fiction. Mr. Penumbra’s 24-Hour Bookstore is exactly what it sounds like: an establishment you have to enter and will never want to leave, a modern-day cabinet of wonders ready to give a jolt of energy to every curious reader, no matter the time of day.

Warning: Major spoilers below!


  • The writing was good. It was mostly entertaining and funny (though at times it was clear the author was trying way too hard). I laughed (or at least chuckled) out loud numerous times along the way.
  • This was a great premise for a book: a secret society of readers trying to decode a 500-year-old problem. Who wouldn’t be interested in that? Too bad the author seemed to have lost his way from the midpoint on.
  • The bookstore was a cool little place. I liked the ordinary interactions between Clay and the customers, as well as the rules he had to follow, the old ledgers, and the handoffs with the afternoon clerk.
  • The description of Clay’s targeted Google ad was a fun little scene. At least it was a unique way to get Kat into the picture, instead of having her just wander into the bookstore on her own.
  • I liked the epilogue telling what happened to everyone. It sounds like the author is planning further adventures for Clay and Penumbra, which I’ll probably end up checking out.


  • The author was way too in love with all things Google. It got a bit tiresome reading about how awesome and advanced and perfect Google is.
  • I didn’t understand why Kat suddenly started giving Clay the cold shoulder. Was it just because she became part of Project Management at Google? Was it because she couldn’t crack the Codex even with all of Google’s high-powered resources? It made no sense.
  • The Dragon-Song Chronicles book-within-a-book gimmick was boring to me. Maybe if I were a sci-fi/fantasy reader, I would have been more interested, but as it was… I wanted to skip everything that mentioned the Dragon-Song Chronicles.
  • The ending was a bit of a letdown. By the time Clay made his big presentation and showed what the Codex Vitae said, I’d already lost interest. There was no sense of urgency, no ticking clock, no real STAKES driving the characters or plot, so I didn’t care anymore. (I just finished the book a few days ago and I’ve already forgotten what the big secret was. I think it was just that the Griffo Gerritszoon will enjoy immortal life through his font, which appears everywhere.)
  • Everyone in the book (with the exception of the Unbroken Spine members) were way too hip and smart for my tastes. They’re the kind of people that annoy me IRL.


Mr. Penumbra’s 24-Hour Bookstore was Robin Sloan’s first book, and it showed. There were lots of promising elements here, but also a number of eye-rolling scenes, developments, and occurrences. Even though this wasn’t quite a page-turner, it was still more entertaining than not. I give it 3 stars out of 5.

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