Rath strikes a rather casual stance and checks his compass, and sure it enough, it is pointing straight towards the entry to the mountain. He hands over his five gold, and with a grim look, heads into the Starless Highway.
Twenty feet wide, smooth as glass on the bottom, with the top and sides just rough hewn, the road leads down rather steeply. There is a single checkpoint about a hundred feet in, with just two guards, each standing next to a single lever. They do not question you and simply wave you forward. You see no gate, portcullis or other device, but surely the levers do something to shut down the passage if need be.
For the next mile, you move deeper and deeper into the mountain. Occasionally there are passages to one side or the other, they are also 15 to 20 feet wide, but these are only 4 to 5 feet high. Doc explains that most connecting tunnels in the dwarven kingdom are designed that way, easy for dwarves to fight in, miserable for taller foes.
The air remains fresh but grows warmer the further you go. The passage slowly levels out, but it is unremarkable other than the endless darkness. Without a light spell, the gloom would soon become unbearable. After several more hours of walking, the passage ahead grows lighter, a deep red glow, and there is a low rumble that throbs through the stone.
Coming out of the tunnel, you enter a huge cavern, hundreds of feet across, with a single fourty foot wide fissure across the entire length of the room. Straight ahead, a sturdy stone bridge crosses the fissure, and from below, is where the red glow and ebbing rumbling seems to eminate. You can see on the far wall, the highway continues on the opposite side of the cavern. This must be the heart of the mountain.
As you eyes adjust, you notice five large boulders just on the other side of the bridge, sitting on a raised mound of dirt. One of the boulders stands up and turns your direction, it is generally humanoid, but as wide as it is tall, about eight feet of both! it just stands there unmoving. As your eyes adjust to the new light, the creature comes into focus.