Wool by Hugh Howey, (2011) This book is science fiction, set in the far future, with people living in 100 story silos without the majority of the people being aware that there are other silos with living people as well. Cartoon villain, but it is hard to write good villains.
This book was a pretty good read, despite my criticisms here. It started out pretty interesting with the world building, but I had a lot of trouble suspending my disbelief that anyone designing silo underground living would NOT HAVE AN ELEVATOR. The whole protagonists must overcome “obstacles” is routine, but usually the obstacles should be believable. 100 stories and lots of equipment and so on, yet no explanation to justify why no elevators. Maybe I missed some sentence or two somewhere offering some lame excuse but I would think that it would be a critical component. However, the desire to have “runners” who pound up and down stairs (geez, not even a DUMBWAITER) to carry stuff and messages is so absurd that it really spoiled the book for me entirely. Of course, I could predict that there would be a fight and that the ability to blockade said SINGLE stairwell would be a crucial plot element (one I just started flipping through yada yada yada). Similarly, it was totally obvious that the second tube [spoiler alert, although of course you will guess before getting there anyway] would have one more person lurking.