“Infra-red film’s comparatively new, isn’t it? And then I’ll bet you have to catch them against that one particular background—you know—or they won’t show on the film. Like trees against clouds. It’s tricky. You must have had just the right lighting that day, and exactly the right focus, and the lens stopped down just right. A kind of minor miracle. It might never happen again exactly that way. But ... don’t look now.” They were silent. Furtively, they watched the mirror. Their eyes slid along toward the open door of the tavern. And then there was a long, breathless silence. “He looked back at us,” Lyman said very quietly. “He looked at us ... that third eye!” The brown man was motionless again. When he moved, it was to swallow the rest of his drink. “I don’t think that they’re suspicious yet,” he said. “The trick will be to keep under cover until we can blow this thing wide open. There’s got to be some way to do it—some way that will convince people.” “There’s proof. The photographs. A competent cameraman ought to be able to figure out just how you caught that Martian on film and duplicate the conditions. It’s evidence.” “Evidence can cut both ways,” the brown man said. “What I’m hoping is that the Martians don’t really like to kill—unless they have to. I’m hoping they won’t kill without proof. But—” He tapped his wrist-watch. “There’s two of us now, though,” Lyman said. “We’ve got to stick together. Both of us have broken the big rule—_don’t look now_—” The bartender was at the back, disconnecting the juke-box. The brown man said, “We’d better not be seen together unnecessarily. But if we both come to this bar tomorrow night at nine for a drink—that wouldn’t look suspicious, even to them.” “Suppose—” Lyman hesitated. “May I have one of those photographs?” “Why?” “If one of us had—an accident—the other one would still have the proof. Enough, maybe, to convince the right people.” The brown man hesitated, nodded shortly, and opened his watch-case again. He gave Lyman one of the pictures. “Hide it,” he said. “It’s—evidence. I’ll see you here tomorrow. Meanwhile, be careful. Remember to play safe.” They shook hands firmly, facing each other in an endless second of final, decisive silence. Then the brown man turned abruptly and walked out of the bar. Lyman sat there. Between two wrinkles in his forehead there was a stir and a flicker of lashes unfurling. The third eye opened slowly and looked after the brown man. [Illustration: The third eye opened slowly and looked after the man]