The tunnel of mirrors behind you, you make your way through the black-stone tunnel.
Eventually, you find yourself in a cavern. It is huge, and nearly empty, but unlike the other rooms and caves you've seen down here, this one is apparently man-made. The walls and floor both are carved stone. The large bricks that make up the floor are uniformly cut, though they appear to be different kinds of rock and range from polished black stone, to a shimmery green, to slate-like gray. The reliefs carved onto the walls are hard to see, but you can make out images of people being eaten by snakes, people being sacrificed on alters, and huge battles that take up several feet of wall.
The wall ahead moves, as do the walls to the sides. With a gasp, you stagger backwards as the entire tunnel in front of you unravels itself, revealing an enormous earthen snake. Instead of scales, there are overlapping stone slabs that move and twist with the rest of it. Its black stone body glints and gleams in the weak light. The snakes maned head moves to inspect you, and its face splits into a wide, toothy grin full to the brim with unnaturally sharp teeth.
"Hello, little mortal," says a voice. The voice does not come from the snake, but seems to come from the walls and rock itself. "I am Slevinius, the serpent of the stone, eldest prince of snakes, the tunnel-maker, the world finder. My bite carries death for the deathless and living alike. Who are you to disturb me?"
You point to your throat and fail to speak.
The giant snake hisses laughter.
"My dearest mother has visited you," he says. "She finds amusement in mortal trinkets. No doubt she is awaiting your arrival to toy with you further. I take it you would have me take you to her?"