Mr. Penumbra's 24-Hour Bookstore by Robin Sloan is utterly charming. I sat down and read it in one enjoyable sitting. I wasn't completely happy with the ending. I wanted more. I wasn't ready to leave the bookstore.
Clay Jannon is desperate for a job. Any job. While out for a walk in the wilds of San Francisco, he sees a help wanted sign in a bookstore next to a strip club. Minutes later he is the new night clerk. It doesn't take long before Clay realizes something very strange is going on. The store is partly a book store and partly a members only lending library. The books being lent are all in code. It turns out that the owner of the story, Mr. Penumbra, and the library patrons are members of a strange cult trying to solve a mystery.
Some of the characters in the book are a little over the top. It's also convenient that Clay's best friend is a multimillionaire. It's also convenient that Clay's love interest works at Google. Without that he wouldn't be able to solve the mystery. I do wonder what she was doing in the bookstore's part of town when she never actually appears there again.
As I said, I didn't like the ending. I wanted Clay to get the girl, get the bookstore and have a great life. The mystery gets solved but the answer is not what anyone expects. It's actually kind of depressing. Even so, the story was enjoyable.