"If they find the opening they'll come looking for us. These Martians are hostile. Some of our men might be killed and they have wives and families." Jean made Rex feel ashamed of himself. "Don't worry. I'll get you out of here." She glanced up at him. Her chin trembled slightly as she sought to stiffen it. At that moment they walked into a larger tunnel. There were more overhead bulbs here and a ribbon of narrow-gauge track stretching off into the distance. "A railroad!" Rex exclaimed. "I wonder where it goes?" "I've got a hunch we're going to find out." One of the Martians had gone around a shoulder of the tunnel. There was a whining sound. He returned in the driver's seat of a small rail car. Barzoo motioned the Terrans into one of the seats. The other Martians got in behind them. The driver pulled a throttle. The whining sound increased and the car moved off down the tracks. Rex listened for a time, inspected the portion of the car within range of his eyes, then said, "I wonder what kind of power this thing uses?" Jean did not answer. Her head had dropped to his shoulder. She was asleep. He settled himself, forming a pocket with his body so she could rest against him with the seat supporting her. Behind him the eyes of the three Martians, including Barzoo, had also closed. Rex wondered if the driver was asleep also. The car rolled on in a monotonously straight line, mile after mile. Rex realized he had discovered a civilization under Mars, the existence of which was unknown on Terra. He knew that none of the authorities or experts suspected anything so civilized as a railroad in the forbidden polar lands. At best they thought the territory inhabited by hardy bands of hostile, backward ice dwellers. This was indeed a great discovery, he told himself bitterly. Of course neither he nor Jean would live to reveal it, but they could die happy, knowing they were great explorers. He grew tired of excoriating himself. The passing overhead lights had a hypnotic effect. He closed his eyes and slept.... Fanton, son of Fandor of the Bantarks—last great ruling dynasty of Mars—lay sick and dying in a foul cell under the Amphitheater of the Gods. He was old and tired and ready to die, yet he longed for survival