about midnight
`` I think so . I placed four of my boys there as a guard -- inside , and out of sight . Nobody was to be hurt -- while outside ; but any attempt to enter -- well , we said just let anybody try it ! Then I went out into the hills and uncovered and cut the secret wires which connected your bedroom with the wires that go to the dynamite deposits under all our vast factories , mills , workshops , magazines , etc. , and about midnight I and my boys turned out and connected that wire with the cave , and nobody but you and I suspects where the other end of it goes to . We laid it under ground , of course , and it was all finished in a couple of hours or so . We sha 'n' t have to leave our fortress now when we want to blow up our civilization . '' `` It was the right move -- and the natural one ; military necessity , in the changed condition of things .