Ahead of me, as I looked back towards the virus factory area, the tracks went straight over the single arch of the steel bridge that spanned the narrow ravine and, slowly dropping, twisted to my left behind a small hill to be lost about a half a mile away. I was lying in the brush on top of the hill that rose in a steep curve out of the gorge. To my immediate right, a deep cutting with jagged rocky walls slashed through the hill from where the bridge jumped the gap. Fortunately for us, the side of the ravine farthest from the virus factory, where I now lay, was much higher than the other, which enabled us to control the approaches. The rise in gradient would also slow the train. It was a marvellous trap. We had crossed the fast-running foamy little river higher up, where it dropped down from the steep mountain ridges. Now, in the cleft below, I could hear the deeper growling as it fought for space among the heavy boulders of its bed. I was tired after the march; tired enough to quit right there. A few feet away, over the reverse slope in a little hollow, Lim On was concentrating on his demolition charges, his skeleton face immobile and thin fingers working surely as he fixed the special fuses. He had finished three, with two to go. Anders had told us there were five tank cars. We had to get them all. I rolled over a little, the better to reach my pants pocket where I had a pair of tiny Japanese field glasses. The sun was warm and, under the special steel of the American-made Russian model helmet, my forehead was wet where the headband touched. Like all the others, I was wearing one of the new lightweight plastic body armor suits under the uniform. It was good to know that even a burp gun bullet would bruise but not penetrate. Only high velocity rifle fire could cut through the flexible weave but I wondered momentarily if it was worth all the sticky discomfort to wear it. The glasses were up to my eyes now and I waited, propped on my elbows. The round magnified world was blurred by the heat waves and the exhaustion which blunted my concentration and sent quick tremors through my tired arms. A fly found me, his feet tickling my face as he sucked the sweat drops. The crawling became intolerable and I had to brush him off. When my eyes adjusted again to the glasses I saw Makstutis and Kim, with seven men. They were filing down the edge of the cutting in full view.