That took fifteen minutes of steady rhythmic exercise, joint by joint and digit by digit, until he was finally satisfied with the coordination. Twenty minutes later he was slipping the clamps loose that held his climbing suit tight to the rock, tucking them into the pack, and beginning a careful ascent. At this height, the appearance of the rock surface was deceptive. Each hand-hold must be carefully tested, each piton placed and checked before any new movement could be made. He had studied the preferred ascent route for so long that the choice of direction and movement had passed below the level of his conscious thoughts. That was dangerous. No amount of prior study could tell of crumbling rocks and moving ice cover. As needed, he made the minor changes to his path, crabbing right and left but always ascending.

By noon he had reached the last, gently-sloping ice field that led to the final summit. He paused there, looking about him at the Karakorum Range. In the clear, thin air, he could see well over a hundred miles. The snow-capped peaks marched endlessly away from him, swelling towards the south-east where Everest stood more than seven hundred miles distant. With his eyes fixed on the jagged peaks he slid down his face mask, loosened the oxygen tube that led from his backpack to the corner of his mouth, and began to eat a cold meal of dry concentrates.

To the south, hovering high in the eye of the noonday sun, a small aircraft hung suspended. It would have been invisible to Rob Merlin, even if he had found reason to squint towards the blinding disc — his photo-sensitive goggles would have darkened too much to see anything but the sun itself. The pilot had placed the craft on automatic control while she fine-tuned the electronic magnifier of the telescope. As she corrected the setting, the figure of Rob Merlin, ant-like in the view-finder, sprang suddenly into sharp focus on the display screen. He was crouched forward, leaning to balance the weight of his backpack. Under the thermal clothing his body appeared stocky and powerfully built, with heavy shoulders and a broad back. The woman watched him in silence as he ate the simple meal.