"I congratulate you upon your recovery, Captain Rennell," remarked one of them with ironical politeness. "Also upon your shrewd coup. Needless to say, it had no chance of success, but we were misinformed as to the hour at which you might be expected. We thought it would take the fools at Washington a little longer to puzzle out our location--and then we did not put quite sufficient force into our hurricane. Quite an artificial one, Captain." Dick, glaring at them, said nothing, and the one who had spoken turned to his companion, laughing, and said something in a foreign language that he did not recognize. "His Majesty the Emperor commands your presence, and that of this old fool," said the first man. "Do not attempt to escape us. Death will be instantaneous." He drew a glass rod from his pocket, the tip of which glowed with a pale blue light. * * * * * Again he spoke to his companion, who moved apparently a few feet distant out on the prairie. Suddenly Dick saw old Evans' chain slacken: then Dick's slackened too. He understood that he was unbound, though his wrists and ankles were still loosely fastened. The second man took his station beside Luke Evans and motioned to him to rise. The first man beckoned to Dick to do the same. The two prisoners got upon their feet, trailing each a length of clanking chain. Each of the two guards covered his captive with the glass rod and motioned to him to precede him. Choking with fury, Dick obeyed. He had taken a dozen steps with his guard uttered a sharp command to halt, at the same time shouting some word of command. The edge of a door appeared, also seeming to materialize out of space. It widened, and Dick realized that he was looking at the unpainted inner side of a door whose outside was invisible. Beyond the door appeared a flight of steps. Dick passed through and descended them. He counted fifteen. He emerged into a timbered underground passage, well lit with lamps, filled with what seemed to be mercury vapor. Behind him walked his guard: behind the guard he heard Luke Evans shambling. Both chains were clinking, and again Dick's fury almost overcame him. He controlled himself. He had no hope or desire for life, but he meant to strike some sort of blow before he died, if it were possible. They turned out of the timbered passage, Dick's guard now walking at his side, the glass rod menacing his back. Dick found himself in a large subterranean room of extraordinary character. The walls were not merely timbered, but paneled. Pictures hung upon them, there were soft rugs underfoot, there was antique furniture. Everything was in plain sight. * * * * * There was a door at the farther end, from beyond which came the murmur of voices. Two guards in the same black uniform, but without the ornamental silver braid, stood to attention, long halberds in their hands. One spoke a challenge.