D&D - War of the Planes
This is the main objective for our heroes.
Orcus is opening portals throughout the realm. These portals, large or small. Will allow Demons or Undead to come through to the mortal plain in full force. This must not happen.
You have been charged by Bahamut himself to close as many of these as possible. There are other out there trying to do the same (such as Minos).
What is required to close these portals:
There is a guardian who has been appointed by Orcus to maintain the portals. Commonly it has been dragons, but there can be others. This guardian is the only one who can open the portal with the item. In order for that portal to be permanently closed, the guardian must be slain. That way he can not create another item to maintain the portal.
The item that is bound to the portal is an item from this realm. It can be anything from the very small, to the very large. Usually it is something that can be carried in order to move it from location to location. It would have to be near the portal in order to activate it. The item must be destroyed in order to close the portal. There is no other known way to close these. The power that holds it is to powerful for anyone in this realm.