From the Game's Introduction:
Beneath the Cold Mountains lies the Tombs of the Ancient Ones. This underground city was built for their dead. One entrance is in the Valley of the Orcs. The other entrance is on the other side of the mountains in the Lands of the Humans. For centuries, this underground complex became a battleground, as one group, then another tried to use it to invade each other's territory.
Several generations ago, a human magician known as the Gray One, cast a powerful spell that stopped the Orcs from advancing past a magical barrier. This invisible barrier ran along one wall of a corridor in the upper level. No Orc could pass through the doors on that wall, yet humans could safely enter and exit through the doors.
For years, small groups of humans have tried to infiltrate the Tombs. The Valley Confederacy has opposed the intruders by setting up traps and guards on the Orc-side of the Tombs. Still, the humans continue to trespass. Many on the council believe once the humans find a passage into the Valley of the Orcs, it will only be a matter of time before an invasion force is sent to the Valley.
As a young Orc warrior from the Forest tribe, you support the Valley Confederacy of Orc Tribes. You gladly perform guard duty in the underground chambers, in order to secure the safety of the Valley. This is the frontline of defense. This is:
The First Level