Mr. Penumbra’s Bookstore is an impossibly narrow shop that has shelving that goes from the floor to ceiling three stories high with only ladders to retrieve the books at the top. The used books it sells at the front of the store are a mix of classics with a few popular titles thrown in, but it is the books from the back of the store that are different, even obscure with unknown authors and titles. The customers who use the books from the back of the store never buy, the books only borrow them, and these quirky customers are always preoccupied, thinking about their research. Mr. Penumbra’s Bookstore needs a clerk to work the nightshift, and on one fateful day quite by accident the ordinary, out- of-work Clay Jannon enters the shop and is given the job.
Clay soon discovers the books at the back of the shop and notices the oddity of those customers, and though his curiosity is piqued he doesn’t open the books- one of the rules of the bookstore is that he was not to read or examine the books. Night after night he watches the customers and wonders what is the secret behind the bookstore? Despite the consequences and unable to contain himself any longer Clay decides with help from his friends to find the answer in Mr. Penumbra’s 24-hour Bookstore by Robin Sloan. Literary and whimsical, this novel moves with deftness as Clay is drawn deeper into the puzzle behind Mr. Penumbra’s Bookstore.