Dialogue in Dostoevsky's Demons

[Anonymous No.20576410]

So far I've been really enjoying the book and I haven't had any trouble at all with the character dialogues. That is, until I reached Part II, Chapter 1, subparts 2 and 3 - basically the parts where we have Stepan Trofimovich recall what he talked about with his son Pyotr Stepanovich, and then the dialogue between Pyotr Stepanovich and Nikolay Stavrogin.
I re-read some parts several times and I just couldn't make sense of a large chunk of what was said. I sense a great deal of anxiety and agitation in both Stepan and Pyotr when they speak, and while this state is somewhat natural for Stepan, it was still odd seeing him speak so disjointedly - I could only glean some sense from his words when he was talking about something revolutionary, but it was really vague and unclear.
Pyotr was even weirder. So far he'd spoken eloquently and to the point and seeing him flustered, shifting his weight from foot to foot and waving his hands while babbling incomprehensibly was jarring.
My question is - am I right to think that he feels intimidated by Nikolay Stavrogin and wants something (vaguely alluded to) from him which makes him act like a fool and babble on and on with no seeming point, or is there something about the dialogues that has evaded me so far? Seeing how Pyotr meandered his way to a few clear sentences at the end of part 3, those about atheism, the Internationale and Fedka, the convict from Siberia, whom Pyotr seems to hint is a possible tool for doing something illegal and untoward, but why?
After the whole showdown on Sunday in the previous chapter I was starting to think all the mystery and intrigue would start unravelling, only to be blasted by pages of anxiety-ridden dialogue about something-but-nothing in particular. What's happening?