I'm having trouble coming up with a solid idea that feels big enough to fit the tone of the books/show.  Some rough ideas, maybe together we can make it cooler...

* Our characters are Rovers and venture into ruins, end up discovering something high tech from the old world.  But they have no idea how to use it.  End up creating a lot of trouble.

* Two druids (maybe set in the pre-Allanon days) are charged with recovering some ancient books.  This could be pretty open.

* ??  I dunno...  what are your creative juices saying?  :hehe