He goes on to explain, in general terms, how the facility is to be built. It is to be a network of intersecting shafts bored through hard volcanic rock. Its dimensions are surprisingly small given the amount of effort that will be spent on building it. They won’t be able to store much here: enough ammunition for a regiment to fight for a week, perhaps, assuming that they make minimal use of heavy weapons, and get their food off the land. But those supplies will be almost inconceivably well protected.