He was saying, "Of course, my boy, I can't compel you to stay at home." The doctor delighted in the vigorous, frank manner and powerful voice of the man; they belonged perfectly with his black hair and bristling beard, his flashing eyes and aggressive nose. "I'd rather you stayed out of this; at the same time, I'd be a proud man if you didn't!" The student calmly finished his dressing. "What time did you tell the men to come?" was all he said; and the father chuckled, then sighed. The two took flight in a small two-seater. It was night, and the doctor took note of the planet's system of signal lights. Within five minutes, however, the flight ended with a landing in some sort of a deep depression; the doctor called it a ravine. Climbing from the machine, the two apostles stepped a few paces in total darkness; then the elder man produced a small electric torch, which he wig-wagged above his head. There was a series of answering flashes at a distance; and next moment a door, let into the side of the ravine, opened right in front of the pair. They stepped in and closed the door after them, then turned their light down a long corridor. Reaching the end of this the doctor noted a loophole in the wall, from which projected something suspiciously, like the muzzle of a machine gun. He had no difficulty in imagining the consequences should some one open that hidden door without first giving the signal. Much as one might enter a lodge-room, the two radicals showed their faces at a port-hole in a door, after which they passed guards with masklike helmets. In a few seconds they found themselves in a brilliantly lighted hall, very large and commodious except for the heavy pillars which supported its low ceiling. It was half filled with men. The elder Ernol had no use for formality. After brief greetings to some kind of a committee, he took his place on a platform; while his son unconsciously gratified the doctor by looking over the crowd. Presumably they were all workers; and in one way they were all alike; the habitual contentment in their faces had been momentarily replaced by excitement. However, they were quiet and well behaved enough. "Comrades," began the radical without delay, "I appreciate your coming here at all, under the circumstances. The commission plainly warned me that any further teaching would be disastrous. I am not sure, but I imagine they would arrest both myself and those found with me. If there is any one who feels that he would rather not take the risk, now is the time for him to go." There was a moment's pause; then, in the back of the hall, two men who had been sitting together got up and hurriedly went out. Ernol waited, but there was no further exodus.