Guerillas (1975) by V.S. Naipaul is only 250 pages long, but it took me close to three weeks to read. It has to be one of the most complicated books I've ever read, and one of the most unsettling.
The setting is never identified specifically, but it can be any former colonized country where there is poverty and political instability and a hot scorching sun. (Naipaul is from Trinidad, so he may have been describing his native country) There is no protagonist nor antagonist, and instead there are a number of characters with flawed personalities. One of the most disturbing characters is a woman named Jane, who is British and came to the country to be with her lover. This description of her is apt:
"She was without memory. . .She was without consistency or even without coherence. She knew only what she was and what she had been born to; to this knowledge she was tethered; it was her stability, enabling her to adventure in security. Adventuring, she was indifferent, perhaps blind, to the contradiction between what she said and what she was so secure of being; and this indifference or blindness, this absence of the sense of the absurd, was part of her unassailability."
And, to me, this description is for a certain sort of ugly developed country foreigner, who does not see nuances and the subtleties between their condition and the condition of the formerly colonized. Because, of course, there are, and they are indelible.