About the same age as Milli, Romehl had recently passed her twentieth birthday test and hence was eligible to marry; so she and a young man named Hakin had requested the fish-masters to give them the requisite permission. But their overlords for some reason had peremptorily denied the request. Romehl and Hakin were desolate. * * * * * Young Abbot's sympathies were at once aroused. "Can't something be done?" he started to ask. But Milli silenced him with a warning glance. "Of course not!" she said. "Who are we to question the judgment of our all-knowing masters?" Romehl had really come to Milli just to pour her troubles into a friendly ear, rather than because she hoped to get any helpful ideas. So she had a good cry, and finally left, somewhat comforted. George and Milli then took up again the problem of saving the outer earth from the threatened invasion. Milli suggested that they go peaceably with the expedition, and then warn the authorities of America at the first opportunity after their arrival; but Abbot pointed out that this would merely result in their both being shut up in some insane asylum, as no one would believe such a crazy story as theirs. The time for lights to be put out arrived without their thinking of any better idea. Next day Milli spent considerable time with Dolf, and on her return excitedly informed Abbot that he had evolved a most diabolical plot. There were sufficient quantities of explosives in storage to blast a hole through the wall of the caves, letting in the sea and killing everyone in the city. Dolf planned to set this off with a time fuse, upon the departure of the expedition. Thus Thig and the people who were left behind--about two-thirds of the total population of the city--would be destroyed, and the fish would have no one to send after Dolf and his followers to dictate to them on the upper earth. Relieved of the thraldom of the fish, Dolf could make himself Emperor of the World, and rule over the human cattle, with Milli at his side as Empress. An alluring program--from Dolf's point of view. * * * * * "I didn't expect such treason even from Dolf!" exclaimed the young American. "We must tell Thig!" "What good would that do?" remonstrated the girl. "If you failed to convince Thig, Dolf would make an end of us both. And if you convinced Thig, it would mean the end of Dolf, whose influence is all that keeps me alive. We must think of something else." "Right, as always," replied Abbot. A growl came from the doorway. It was Dolf, his bearded face black with wrath. "So?" he sputtered. "Treachery, eh?" He whistled twice and two guards appeared.