The road was good, and we made the march to the summit in little over two weeks. The last four days were terrifying. Our food ran out, and the soldiers were forced to slaughter pack animals.

Alexander had been right. If we'd made it in fourteen days, it would have been perfect. Unfortunately, it took sixteen. Those two extra days for us would mean six days for the men in the back, and that was a week with no food. Alexander sent messengers back to stop the food from coming to the front of the line. Seeing how close we were to the top, he decided to cut off our supplies and press onwards. That meant that after our food ran out we would have no more until we reached the fertile valley below the pass.

Now began a race against time. Twenty thousand men, ten thousand horses, three hundred camels, five hundred mules, and one time-traveler made the march up the mountain in less than two days. We traveled eighty kilometers up a mountainside in less time, I thought, than it would have taken to drive a jeep. Each man who fell was loaded instantly onto a horse, each horse that fell was left behind to fend for itself until the second half of the army found it, and each donkey that fell was slaughtered and the meat eaten for dinner that night.

We walked from before dawn till after dusk, ate the last of our victuals, and slept wrapped in our cloaks with the warmth of other human bodies keeping us alive.

As they walked, soldiers picked herbs and stuffed them in their belts. They were professionals, and knew all the medicinal plants and which ones were edible.

With the cold so intense and the air so rare, the men started getting nausea and headaches. My nose bled constantly, which annoyed me, but it cheered the men up immensely. In those days nosebleeds were considered a sign from the Gods, and they all took heart each time I had a scarlet stain dribbling down my chin and chest.

Alexander decided to march in intermittence all through the day and night, and so we marched one hour, rested one hour and so on, until we reached the top of the world.

The last ten kilometers were the worst. Bitter wind met us head-on. Funneled through the pass, it seemed as solid as a wall of ice. We leaned our heads into it and felt the cold right through our skulls.

Alexander was on foot, leading his valiant horse, when Bucephalus staggered and nearly fell. Blood sputtered from his nostrils in a crimson gush and Alexander stared, his face white with shock, as his horse sank to his knees. For several minutes the men right behind us held their breaths. No one spoke and the army ground to a halt as Alexander struggled to unfasten the horse's harness, his hands shaking and tears freezing on his cheeks in the harsh wind. Luckily Bucephalus recuperated quickly, and soon he was back on his feet, his eyes puzzled, as if he didn't know quite where he was or what had happened. We could see the summit only a few dozen feet away, but Bucephalus's malaise put a damper on Alexander's joy at reaching the top.

Some men were afraid to venture over the rise, believing that the ends of the earth were right there. Even Alexander, whose unquenchable enthusiasm for adventure had led him this far, seemed unsure of himself. He was also shaken by his horse's fall. He wrapped his arm around his stallion's neck, and together they walked towards the summit. We all stood back. It seemed fitting.

The two figures were silhouetted against the monstrous sky. On either side was emptiness. The sun was just starting to set, and on the opposite horizon the rising moon was clearly visible. It seemed as if he were alone on the top of the earth with only his horse, the sun, and the moon for company. Then he turned to face us, and he raised both arms in triumph. The way was clear. He'd gotten through. The road to Bactria was open. We poured through the pass in a trickle, then a rush as the men hurried to see the marvels that were beyond the mountains.