Six gruesome blades forged from dwarven blood in the pits of ancient bol-Pakash. Six knives the dwarves wish never existed.
Maddoc sat amid a pile of unrecognizable corpses. Men, Dwarves, Orcs, you couldn't tell. He periodically took a stab at one with his new knife and screamed, "STOP LAUGHING AT ME!"
An otherwise simple spear, the dread blade of Hatred brings rot and decay to all it strikes, be it armour, body, or soul.
A dark dagger of song, forged for vengance. It shall have that vengance.
A dagger that makes the user think that he is invisible.
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?