"Well, I can't see anything to do but to follow our regular methods," Wade said slowly. "We'll send word out to the banks and stores to watch for this method of robbery as well as possible, and we'll put a man to look into Harkness and his story, and broadcast a list of the bills' numbers if we can get them." When Fear Broods O'er Us Grantham shook his head impatiently. "Wade, these ordinary police methods of yours are utterly useless in a case like this. It's all right to gather fact after fact and slowly apprehend an ordinary criminal in that way, but this is not a case of catching a criminal so much as a case of war! War between this city and the Invisible Master! And the one hope of catching him lies in making the whole city realize that the Invisible Master is at large in it, and so put them on their guard against every unusual incident that may point his presence." "It seems to me," Wade said dryly, "that when Carton here and his colleagues get through with this story there's going to be mighty few in the city who don't know that the Invisible Master's at large." And by that night, indeed, all New York was aware through the screaming newspapers that the Invisible Master had begun his threatened activities. He had, apparently, deliberately chosen for his first exploit one most calculated to win for himself the city's amazed attention, in his astounding robbery of the great bank in the full light of day. The thing was stupefying. It was the one subject of excited discussion in the city that night. It was the Invisible Master's work, that was certain. But when would he strike again, when would he make another of these astounding coups? Imagination ran riot in the depiction of the things that the Invisible Master might do. People were warned to go always on the assumption that he was near, for caution's sake. Scientists and pseudo-scientists gave forth sensational interviews on how the Invisible Master might be caught. The newspapers sought above all else for information from Dr. Grantham, the man who had unwittingly loosed the terror upon the city. It was announced late that day that Grantham was foregoing all other activities to devise a plan for curbing or capturing the Invisible Master. Some suggested even that he was making another projector with which one invisible man could hunt the other, forgetful of the fact that Dr. Grantham's first projector had been the work of months, as he admitted. Carton, sent that night for information from Grantham, had evidence of the importance attached to him in the policemen at the door of the physics building, and knot of reporters lounging outside. They hailed him noisily and called after him when Carton, after sending his name in, was admitted inside. He found Grantham in his laboratory's ante-room, with Sergeant Wade.