Rejoicing in the sudden turn in affairs, the two guilty men were building castles in the air with their ill-gotten wealth, when heavy footsteps came up from the office stairs; there was a knocking at the door. The two men started up. Their nerves were humming still from the strain of the past day and night. "Come in," Asherton-Smith cried unsteadily. A couple of men entered. One of them had a paper in his hand. "Mr. Asherton-Smith and Mr. Carl Ericsson, _alias_ James Jones," he said, "I have a warrant for your arrest which I will read to you presently. I warn you not to say too much. Your accomplice, Jacob Peters, has been arrested at Cape Town, and I am instructed by cable that he has made a full confession." The snarling oath died away on Ericsson's lips. "It's all up," he said hoarsely, "but it was a chance. Curse Peters for a white-livered fool. But for him I should be worth fifty millions." THE INVISIBLE FORCE. A Story of What Might Happen in the Days to Come, when Underground London is Tunnelled in all Directions for Electric Railways, if an Explosion Should Take Place in One of the Tubes. I. It seemed as if London had solved one of her great problems at last. The communication difficulty was at an end. The first-class ticket-holders no longer struggled to and from business with fourteen fellow-sufferers in a third-class carriage. There were no longer any particularly favoured suburbs, nor were there isolated localities where it took as long getting to the City as an express train takes between London and Swindon. The pleasing paradox of a man living at Brighton because it was nearer to his business than Surbiton had ceased to exist. The tubes had done away with all that. There were at least a dozen hollow cases running under London in all directions. They were cool and well ventilated, the carriages were brilliantly lighted, the various loops were properly equipped and managed. All day long the shining funnels and bright platforms were filled with passengers. Towards midnight the traffic grew less, and by half-past one o'clock the last train had departed. The all-night service was not yet. It was perfectly quiet now along the gleaming core that lay buried under Bond Street and St. James's Street, forming the loop running below the Thames close by Westminster Bridge Road and thence to the crowded Newington and Walworth districts. Here a portion of the roof was under repair. The core was brilliantly lighted; there was no suggestion of fog or gloom. The general use of electricity had disposed of a good deal of London's murkiness; electric motors were applied now to most manufactories and work-shops. There was just as much gas consumed as ever, but it was principally used for heating and culinary purposes. Electric radiators and cookers had not yet reached the multitude; that was a matter of time.