((damn it, this was supposed to have posted just after you made it down.  Oh, well, it still applies, even if you're running, and Koh is following))<br/><br/>Running does the trick, apparently; it was only the ceiling of the ramp passage that was silently collapsing.  As they enter the lower level, the third active mine level of the 5.5 or so levels available, the main ramp passage just kind of melts closed, like the ceiling was taffy.  Once the passage is sealed, the ceiling stops, and becomes solid, stable rock again.<br/><br/>This is not the only access upward, but the other ramp is on the far end of the mine, possibly as much as a mile away in a straightaway (of which no straight passage exists).  There are several vertical winch sites and, of course, the Water Wheel dips down this far to collect seepage water.  None of them are anywhere close, however.<br/><br/>And there's the distant echo of that slithering sound again.