"Disarm it, and then get the front door open. I'm leaving." Foster's eyes flicked over the clothes I was wearing. "So I see," he said. He looked me in the face again. "What is it that's frightened you, Legion?" "Don't act so innocent," I said. "Or am I supposed to get the idea the brownies set up that booby trap while you were asleep?" His eyes went to the gun and his expression tightened. "It's mine," he said. "It's an automatic arrangement. Something's activated it—and without sounding my alarm. You haven't been outside, have you?" "How could I——" "This is important, Legion," Foster rapped. "It would take more than the sight of a machine gun to panic you. What have you seen?" "I was looking for a back door," I said. "I went down to the cellar. I didn't like it down there so I came back up." "What did you see in the cellar?" Foster's face looked strained, colorless. "It looked like ..." I hesitated. "There was a crack in the floor, noises, lights...." "The floor," Foster said. "Certainly. That's the weak point." He seemed to be talking to himself. I jerked a thumb over my shoulder. "Something funny going on outside your windows, too." Foster looked toward the heavy hangings. "Listen carefully, Legion," he said. "We are in grave danger—both of us. It's fortunate you arose when you did. This house, as you must have guessed by now, is something of a fortress. At this moment, it is under attack. The walls are protected by some rather formidable defenses. I can't say as much for the cellar floor; it's merely three feet of ferro-concrete. We'll have to go now—very swiftly, and very quietly." "OK—show me," I said. Foster turned and went back along the hall to one of the locked doors where he pressed something. The door opened and I followed him inside a small room. He crossed to a blank wall, pressed against it. A panel slid aside—and Foster jumped back. "God's wounds!" he gasped. He threw himself at the wall and the panel closed. I stood stock still; from somewhere there was a smell like sulphur.