Lois Clary is a software engineer at General Dexterity, a San Francisco robotics company with world-changing ambitions. She codes all day and collapses at night, her human contact limited to the two brothers who run the neighborhood hole-in-the-wall from which she orders dinner every evening. But when visa issues force them to close up shop, they give Lois their culture, the sourdough starter used to bake their bread. Soon, not only is she eating her own homemade bread, she’s providing loaves to the General Dexterity cafeteria every day. Then the company chef urges her to take her product to the farmer’s market --- and a whole new world opens up.

Clay Jannon has landed 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 the store is even more curious than the name suggests. He concludes it must be a front for something larger, and soon he’s embarked on a complex analysis of the customers’ behavior. It turns out the secrets extend far outside the walls of the bookstore.