human
Write a detailed description of a depressing scene inside a tunnel cavern with water, granite and rubble.
assistant
Passage to the east is blocked by tons of fallen granite. The rubble has cascaded down from above to choke the tunnel and render it totally impassable. The water seeps in underneath the rubble, leaving a sickly green discoloration on the lower pieces. The collapse must have happened long ago, though, for even the upper portion of the pile displays no dust. The finer particles must have been carried down to the floor long ago by the gentle rising and falling of the water level.