Polemic, passionate in a one-note way, pleading, to an extent that sacrifices the narrative. Two great examples from Krakauer: _Under The Banner Of Heaven_, which veers into a straight-up litigation against the Mormon faith†, and _Where Men Win Glory_, whose latter third is practically tear-stained.

Note: I'm not saying either of those books are bad; I liked them. I loved _Into The Wild_.

† I'm not one.