When I came to the edge of the clearing, I stopped, my eyes probing the morning grayness. Then I stepped quickly out of the brush. Suddenly I stopped dead, afraid even to breathe. Two feet from me an Indian dozed, a rifle across his lap. It was too late; his eyes blinked open. I hurled myself on him. There was a brief scuffle and then he lay still, knocked unconscious by the butt of my .45. I faded back into the undergrowth and waited. I thought I heard the door of the cabin in the clearing open. But nothing happened. I let out a deep breath and started skirting the clearing, keeping in the shadows until I was in front of the ramp-like runway. I stared hard at it, trying to make out the details. At the top of the sloping track was a cylindrical mass, the size of an oil drum. It reminded me instantly of the beer-barrel nuclear reactor, a portable affair, developed by the British physicist Robert Parker. Its purpose dawned on me: This was the trigger of the atomic gun that Chetzisky held at the temples of a planet. I moved in for a clearer view. As I did I was brought up abruptly by a calm, even voice, its tone of command sharpened in the crisp morning air. "You needn't move any more, gentleman. Just raise your hands." I looked in the direction of the speaker, as my hands went up. Out of the shadows in front of us emerged a short man with a rifle. Chetzisky! At last! Bundled in a heavy mackinaw, wearing a fur cap with ear muffs, wool socks rolled over the tops of his high boots, he looked grotesque, hardly the intended assassin of a planet. More like a farmer who's waited through a winter night to catch a chicken thief. "What are you doing here?" he asked sharply. In his tone I detected a worried uncertainty. I decided on the bold approach. "Where is Professor MacRoberts?" I demanded sternly. Chetzisky lowered his rifle slowly. He seemed surprised; relieved too. "You're looking for Doctor MacRoberts?" "Yes, the University became worried about him and hired me to find him, fearing he might be ill or lost in this wilderness." "How did you come to track him here?" Chetzisky cocked his head to one side and squinted at me suspiciously. "Well, it happens, sir, that I'm a private investigator, specializing in missing persons," I lied with gusto. "When the University hired me to locate MacRoberts, I interviewed the man's friends, talked with the Indians, etc. And behold, here I am." I grinned broadly with affected boastfulness. Chetzisky eyed me intently. I felt grateful for my mask of beard at that moment. "You came alone?" he asked, relieving me of the automatic in my belt. I nodded. The Doctor put down his rifle. "I'm sorry to appear threatening. But I have reasons. Will you come into my cabin?" * * * * *