Hugh shook his head. "No. The story is that there was a big ship loaded with people from Earth. That's true, of course, because the ship is still here, what's left of it. And so are we. Some of the people on the ship were settlers and some were convicts." He pronounced the word with the same hatred and scorn that always accompanied the name "Korin." Trevor said eagerly, "They used to do that in the early days. Use convict labor in the mines. It made so much trouble they had to stop it. Were the Korins...?" "They were the convicts. The big ship crashed in the valley but most of the people weren't killed. After the crash the convicts killed the men who were in charge of the ship, and made the settlers obey them. That's how it all started. And that's why we're proud we're slaves--because we're descended from the settlers." Trevor could see the picture quite clearly now, the more so because it had happened before in one way or another. The emigrant ship bound for one of the colonies, driven off its course by the tremendous magnetic disturbances that still made Mercury a spaceman's nightmare. They couldn't even have called for help or given their position. The terrible nearness of the Sun made any form of radio communication impossible. And then the convicts had broken free and killed the officers, finding themselves unexpectedly in command of a sort of paradise, with the settlers to serve them. A fairly safe paradise, too. Mercury has an infinite number of these Twilight valleys, all looking more or less alike from space, half hidden under their shallow blankets of air, and only the few that are both accessible and unmistakable because of their size have permanent colonies. Straight up and down, by spaceship, is the only way in or out of most of them, and unless a ship should land directly on them by sheer chance, the erstwhile prisoners would be safe from discovery. "But the sun-stones?" asked Trevor, touching his forehead. "What about the sun-stones and the hawks? They didn't have the use of them when they landed." "No, they came later." Hugh looked around uneasily. "Look, Trevor, it's a thing we don't talk about much. You can see why, when you think what it's done to us. And it's a thing you shouldn't talk about at all." "But how did they get them in their heads? And why? Especially, why do they waste them on the hawks?" * * * * * Jen glanced at him somberly from the circle of Hugh's arm. "We don't know, exactly. But the hawks are the eyes and ears of the Korins. And from the time they used the first sun-stone we've had no hope of getting free from them." The thing that had been buried in Trevor's subconscious since last night's questioning came suddenly to the surface.