You (Uther Lightbringer) are in command of the indigo (violet human) garrison of the 6th circle. The high lord of the white tower has just self immolated himself after gazing in despair, thru the crystal sphere (Palantiri), over the vast armies of the horde that have just landed in the eastern bank of the river. Rumours fly from the dying outlying villages and farms which tell of the crimson (red orc) fury of the mighty Orcs, Uruk-Hai, Giant Trolls accompanied by a fire breathing demon and the undead Knight laying waste to whatever crosses their path.
It is up to you to rally the Silver Garrison (white) by riding up north and lifting the morale of their shattered commander (Lothar) to bring him to your fold. He will tell you of pacts made with southern iron mountain dwarves and the the alliance with the gold (orange dragons) dragon Thurimbrar and his brethren. You must then send a messenger south to seal this alliance.
In the meantime, the White lords son is deep in the forest returning from the Eastern Dark lands. He receives the message of the fate of his father, the White Tower's lord, and he despairs. A village to the south is under attack from the foul horde. Will he go south and come to their aid knowing that in doing so he dooms his small, though doughty band of warriors? Should he go west and hide behind the safety of stout dwarven made walls, to sally forth the garrison when the muster is sufficient? What lies Northeast?
From a town in the southeast, it is rumored that the dark horde has sought the alliance with Bruim, the Blue dragon and his brethren, flying down from their mountain fortress. Rumor or not, it will have to wait...
Notes
This is the first scenario I've created in any game and all comments and suggestions are welcome. The basis for this scenario can be gleaned from the title for those who follow fantasy stories and the like. I would have liked to have put in a bigger castle with seven circles of walls but size constraints and playability made me settle on four. The southern dwarves are actually orcs but for our purposes, they are dwarf axethrowers and dwarf warriors. This was necessary in order to have variety and of course, to have dragons on your side as well. Have fun!