Sure, it was used to predict the future, but no, you're not going to get great marching armies of skeleton out of it.
Except -- hmmm -- I've got one character explaining to another that sure, you start by consulting the dead, maybe getting told where to find treasure, or whether the harvest will fail, but then you send a little ghost to spy on your lady love, and then one to haunt your rival, and one thing leads to another and then you have gigantic armies of skeletons marching across the country because you ran out of the gold you first found and can't hire men (and to think you thought you were set for life when you found that trove).
Now I just gotta find out which characters are talking about it. May even be a work in progress. . . .