Holy crap that's a lot of items! How long have you been playing? o_o
I gotta make writs of passage a little less common... that frequency doesn't really fit the flavor.
Anyway it's not a viscerturgy book problem, turns out, though that was a pretty good guess. It's an "I stupidly forgot to add a line of code to the non-bug-test version of the slime cave card" problem. And yes I'm aware there's some irony in the fact that my bug testing efforts so far have CAUSED all the bugs in the final release version--story-breaking bugs no less. Still, it's kind of heartening to hear that you liked the game so much despite major storylines being unplayable!
I want to fix a few other minor problems before harassing everyone with another bug fix, but an update with a fully playable slime storyline should be out in the next few days. Thanks so much for letting me know this was broken!