The queen of a pocket kingdom, Zora is known for her command of dark magics, fashion sense that involves using armor grade metal in dresses and bustiers, and the stark contrast of her pale skin against her blood red lips and raven dark hair.
Often PCs get on the wrong side of powerful users of magic or break into enchanted tombs, either may get them on the wrong side of a curse.
After the PCs defeat (or force the rapid retreat of) a villanous necromancer/demon summoner, they discover a book. This book outlines how to summon a demon whose power increases according to the size of the summoning circle used to summon it. And after the PCs examine a map of the country, they find that the layout of the cities and roads match up with the required summoning circle. In fact, the final road that would complete the circle is currently in construction.
With anyone who can find out about the circle and the ritual to summon the demon able to somehow make the final road/line, and destruction of the cities and roads currently in existence out of the question (unless this is an evil campaign- that removes the moral quandary), how are the PCs going to solve this problem?