"Yes, we saw it too. We came up just as it was stalking away. It's the first we've ever seen, but we have heard much about them; the stories have been handed down. There is supposed to be a great temple on the dark side, where the robots are housed." "More of them?" Mark exclaimed. "I hope they stay over there, then!" Donli shook his head. "This I know: if the robots are roaming again, as they did many years ago, none of us will be safe." "Then let us go to your city," Brownell put in. "We should be able to lift gravs now, if the Tuner hasn't been damaged." It hadn't been. In a few minutes they were winging low across the plains to the horizon. The city bore the unusual name of "Frell", and lay semi-circularly at the foot of a sharply rising hill. People were seen, men and women alike, working in the surrounding fields. Donli led them through the main street. The buildings were of a dark substance that might have been earth compressed to concrete hardness. They entered the most imposing of these buildings, and thence to a huge room which was almost the size of a theater on Earth. "Make yourselves at ease," Donli said, "while I summon Mari. She will probably be at the laboratories now." "Mari," Driscoll said, when Donli had gone. "So their leader is a woman! And they have laboratories!" They gazed about them. The curious daylight came through windows of glass or similar material. There were chairs and tables of finely-wrought metal. Along one wall were bookcases filled with charts and uniquely-bound volumes. There were other volumes too, which seemed vaguely familiar. Brownell walked over there. "Look at this! A whole case full of books from Earth--scientific, technical books, all of them!" He read a few of the titles on the faded bindings. "These were all popular hundreds of years ago. And these others," he waved, "are probably the entire recorded history of these people. I'd give anything to look into them." He didn't touch the volumes, but remained thoughtful. Mark too was thoughtful. "Frell," he mused. "A strange name for this city. Seems as though it ought to mean something, but I can't quite place it." * * * * * Donli returned soon, accompanied by Mari. She was tall, lithesome, her features classical and still beautiful despite smudges of sweat and grime from the laboratory. Her golden hair was braided into a halo which gave a queenly appearance, and her eyes were bluer than the strange daylight of this world. Skirt and tight-fitting bodice were of rough texture but dyed a rich golden color. Involuntarily the men gasped, but Mari did not mind that or their stares. She seated herself and bade them be seated opposite her. Then she leaned forward, searching their faces. Not until then did they notice that her eyes were cold, suspicious. "You have come from Earth, of course. And Donli tells me this strange one is Martian. Who is leader among you?"