"We have scans," Bill replied. "Not a ton of detail, but essentially the middle hundred yards or so of the segment boundary is a diaphragm, similar to a camera shutter. I think if it was activated, it would close off the segment right to the central cylinder. And you can see two sets of guy-wires or pylons or stays of some kind attached to the central cylinder, if you engage telescopic vision. One set on either side of the central line of the mountains."