If you're only concerned with joining the RP for what's happening right now, go ahead and ask for summary. Most players should be able to tell you what's going on. If you joined for the story, and it's 800 pages long? Well, I guess you can still just drop in from the current event, but with that much text I think that trying to figure out major events from the past would be good to know too. I can understand why you'd want to read all 800 though; sometimes players may have forgotten or never used a bit of information that you just know you can act on, you just need to figure out how or what happened to it between than and now. Maybe you don't want to just feel like that complete newb who i walking into the unknown; you want to feel like you actually have a reason, a place, to be there. A summary is good if you want to know what you missed. But if you really want to be more than just a tact on addition to this 800 page epic, don't be afraid to do a bit of digging and asking. See if you could be someone's lost sibling or their mysterious benefactor, if they have something like that.