They discovered some items in a defunct Mage's Guild building and had to figure out how to use them to locate the place where two ley lines meet.
And here's the breakdown of how it worked:
1: The items as they discoverd them, a folded up piece of parchment with a leather cord around it with some sort of stone ring on the cord, and a small pouch.
2: It's a map! I spent about 3 hours on it, not finished yet, need to finish shading with watercolor pencils, write in city/region names and add the rest of the glyphs, only two were needed first campaign. The pouch contained two red gems with markings.
3: The "stone" (actually sculpey) ring had eight runes on it and two holes drilled through it. The gems had each a large dot, a line and a series of smaller dots (2 and 3).
4: On the map are glyphs inked in red and brown. They each have a distinct number of dots in their design (2 and 3).
5: The large dots align to north, and the players had to match the number of small dots to the glyphs. Once the gem is placed over the glyph, the red lines vanish and only the relevant rune part is visible, which once viewed with the line on the gem, forms one of the runes from the stone ring.
6: Once they figure out which rune it matches, they place the ring over the glyph with the proper rune oriented north. The drilled holes show where to mark down dots.
7: Once the dots are mared, the ring is removed.
8: Draw a line through the dots!
9: Do the same with the second glyph, and you find a point where the two lines intersect! Better pack up your gear, it's roadtrip time!
. I also agree with what someone else said in the thread about the font being a bit hard to read at first glance. It looks really elegant and stylish, but I think a lot of players would prefer something more legible. 
