I don't know how the weather is where you are, but here on my side of the hill in deepest, darkest Brooklyn, we had quite the lightening storm. I was sketching ideas for my shrinking violet experiment when I heard an ear-splitting crash.
It might have been lightening striking. It might have been a dragon-gone-crazy. I might never know what happened, really. It doesn't matter. What does matter is that there is now an additional opening in the catacombs. And that opening reveals a small canal.
It's a small opening, about the size of a medium-sized ottoman, and the temperature within is approximately ten degrees colder than the rest of the catacombs.
The canal seems to be running east/west.
I am gathering supplies and beginning my explorations at sun up.