You're not sounding the least bit "dumb", GeeGee--what would be
really dumb would be for you not to ask a question when you really want to know the answer!!!
The XPack won't interfer with playing Prime at all. Just go right through to the end of Prime, and then when you're ready, click on the To D'ni icon. Here's the first paragraph of the walkthrough here at GameBoomers, just to give you an idea of what happens: "You begin the game in your Relto. Go inside the hut. On the bookshelf to the right is a new book written by Yeesha where she comments on the restoration efforts and on its sad results. After reading it, go to the left bookshelf and click on the blue book with the golden spiral on its spine. Turn to the first page of the book and link to the neighborhood. Welcome to Bevin."
Since you installed the whole package at one time, I suspect that book on the right shelf and the blue one with the golden spiral are accessible right now in your Relto, but I wouldn't fool around with them until I'd finished Prime. I think it would get pretty confusing if you were trying to play both games at the same time, although I guess you could if you wanted to.
My advice would be to finish Prime and then go on to XPack 1. Finish that and then do XPack 2. And when that's done, you can join the rest of us in looking forward to Myst:Revelation... <img border="0" alt="
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