Yes, it's the whole atmosphere that's perfect for me. There's a clod of absurdity, silliness even, that the reader can feel but not the characters and it permeates the whole book. The first time I've read it I had the feeling that there was something wrong under all of it and I kept reading waiting for it to unravel, when I arrived at the last chapters and finished the book it dawned on me that I was a victim of the fortress as well, if you know what I mean.