Well, I hope I can be of a little help here ^^' You write a completely different genre than I do, and one that I haven't really looked into a lot. And I'm still struggling to figure out what advice you're looking for.

I think maybe what you might want to try is more showing and less telling--maybe you could use flashbacks to demonstrate something that's happened, and cut back showing that the character learned this "So and so nodded as they took in the story" or something like that.

When you say, "some details that are already known", are they known to the reader? Or are the character and the audience learning these details at the same time?