Books that pull you in and flesh out complex ideas in very few pages?

Some books I have already read and liked that I think meet the requirements:
* A Psalm for the Wild Built
* I Who Have Never Known Men
* The Old Man and the Sea
* Poison for Breakfast
* This is How You Lose the Time War
* Nothing to See Here

I am not looking for short stories unless you have a particularly good one.

I generally read horror and mystery/thrillers. But the above books don’t really follow that trend.