I am reading (listening) Katabasis for my work book club and it is...a slog. I'm about a third of the way in and as far as I'm concerned both of these people can stay in Hell forever, I really don't care if they ever make it to the end of their quest.
(It doesn't help that the overriding metaphor here is "graduate school is Hell" and so me being also in the middle of a BtVS rewatch means I'm getting two "school is Hell" metaphors at once, only one of them is way way more fun. )