"You mean their fighting-machines," Sherman replied. "Why, I'm not absolutely certain. I only know what I picked up from them and what Marta Lami"--he swallowed hard at the mention of her name--"the bravest woman in the world, told me. But I think that a shell with a lead cap would go through those fighting machines like a knife through a piece of cheese." There was a tiny silence in the room at this momentous announcement. Then an artillery officer said, dreamily, "The armor-piercing shells the railroad guns use have lead caps." As though his words had released a spell there came a quick drumfire of questions: "What are they armored with?" "What kind of a power-plant do they use?" "Can you stop the light-ray?" "What makes you think so?" Sherman smiled. "Just a moment. One question at a time. I'm not sure I can answer them all, anyway. As to what makes me think so and what they're armored with, they have a coating of steel armor, but it isn't very thick. It's plated on the outside with a coat of lead and outside that with the substance they call 'pure light.' I don't know what it is, but it's the same stuff they use in the light-ray and in their shells, and I know that lead sheeting will stop it, even when the lead is very thin." General Grierson swung round in his chair. "Hartnett! write out an order to General Hudson, Chief Quartermaster, at once. Tell him to remove every piece of lead he can find in Atlantic City and get it melted down. Also to set up a plant for tipping all shells with lead...." Ben Ruby leaned forward. "Can we get into their city, their headquarters, or whatever they call it?" "My God, I hope so!" cried Sherman. "Marta Lami's in there." "All right, young man, you'll have your chance for that," said General Grierson. "Now suppose you tell us as much as you know about these--things. Every bit of information we can get will be valuable.... Oh, by the way, Hartnett. Have an order made out to the infantry to cut the points of their bullets with their knives. That will make them dum-dum and bring the lead out. Also another one to evacuate as much infantry as possible. They aren't going to be a great deal of use...." * * * * *