Nobody knew what to do; everybody had lost their heads for the moment. It seemed hopeless from the very start. Naturally, the man that everybody looked to at the moment was Fergusson of the associated tubes. With him was Alton Rossiter, representing the County Council. "But how to make a start?" the latter asked. "We will start from Deptford," said Fergusson. "We must first ascertain the exact time that the train left Deptford, and the precise moment when the first explosion took place. Mind you, I believe there was a series of explosions. You see, there is always a fair amount of air in the tubes. When the inflowing gas met the cross currents of air, it would be diverted, or pocketed, so to speak. We should have a big pocket of the explosive, followed by a clear space. When the switches were turned on there would be sparks here and there all along the tubes. This means that practically simultaneously the mines would be fired; fired so quickly that the series of reports would sound like one big bang. That this must be so can be seen by the state of some of the streets. In some spots the tube has been wrenched bodily from the earth as easily as if it had been a gaspipe. And then, again, you have streets that do not show the slightest damage. You must agree with me that my theory is a correct one." "I do. But what are you driving at?" "Well, I am afraid that my theory is a very forlorn one, but I give it for what it is worth. It's just possible, faintly possible, that those trains ran into a portion of the tube where there was no explosion at all. There were explosions behind them and in front of them, and of course the machinery would have been rendered useless instantly, so that the trains may be trapped with no ingress or outlet. I'm not in the least sanguine of finding anything, but the aftermath of a fearful tragedy. Anyway, our duty is pretty plainly before us--we must go to Deptford. Come along." The journey to Deptford was no easy one. There were so many streets up that locomotion was a difficult matter. And where the streets were damaged there was danger. It was possible to use cycles, seeing that the rubber tires formed non-conductors, and indiarubber gloves and shoes allowed extra protection. But the mere suggestion of a spill was thrilling. It might mean the tearing of a glove or the loss of a shoe, and then--well, that did not bear thinking about. "I never before properly appreciated the feelings of the man that Blondin used to carry on his back." Rossiter said as the pair pushed steadily through Bermondsey, "but I can understand his emotions now." The roads, even where there was no danger, were empty. A man or woman would venture timidly out and look longingly to the other side of the road and then give up the idea of moving altogether. As a matter of fact there was more of it safe than otherwise, but the risks were too awful. VI.