"Keep moving, damn you!" I whispered. The swearing worked. The gusty wind pushed the paper on. I crawled a few feet and pressed myself into a shallow depression behind the slab. The Bolo churned closer; a loose treadplate was slapping the earth with a rhythmic thud. The burning paper was fifty feet away now, a twinkle of orange light in the deep twilight. At twenty yards, looming up like a pagoda, the Bolo halted, sat rumbling and swiveling its rust-streaked turret, looking for the radiating source its IR had first picked up. The flare of the paper caught its electronic attention. The turret swung, then back. It was puzzled. It whooped again, then reached a decision. Ports snapped open. A volley of anti-personnel slugs whoofed into the target; the scrap of paper disappeared in a gout of tossed dirt. I hugged the ground like gold lame hugs a torch singer's hip and waited; nothing happened. The Bolo sat, rumbling softly to itself. Then I heard another sound over the murmur of the idling engine, a distant roaring, like a flight of low-level bombers. I raised my head half an inch and took a look. There were lights moving beyond the field--the paired beams of a convoy approaching from the town. * * * * * The Bolo stirred, moved heavily forward until it towered over me no more than twenty feet away. I saw gun ports open high on the armored facade--the ones that housed the heavy infinite repeaters. Slim black muzzles slid into view, hunted for an instant, then depressed and locked. They were bearing on the oncoming vehicles that were spreading out now in a loose skirmish line under a roiling layer of dust. The watchdog was getting ready to defend its territory--and I was caught in the middle. A blue-white floodlight lanced out from across the field, glared against the scaled plating of the Bolo. I heard relays click inside the monster fighting machine, and braced myself for the thunder of her battery.... There was a dry rattle. The guns traversed, clattering emptily. Beyond the fence the floodlight played for a moment longer against the Bolo, then moved on across the ramp, back, across and back, searching.... Once more the Bolo fired its empty guns. Its red IR beams swept the scene again; then relays snicked, the impotent guns retracted, the port covers closed. Satisfied, the Bolo heaved itself around and moved off, trailing a stink of ozone and ether, the broken tread thumping like a cripple on a stair. I waited until it disappeared in the gloom two hundred yards away, then cautiously turned my suit control to vent off the heat. Full insulation could boil a man in his own gravy in less than half an hour. The floodlight had blinked off now. I got to my hands and knees and started toward the perimeter fence. The Bolo's circuits weren't tuned as fine as they should have been; it let me go. * * * * *