We got back to the airfield early. But Sunday morning passed, with no fuel. We were taken to the huge cafeteria for lunch, where we sat among the hundreds of blue-uniformed workers and ate our rice and stir-fried pork with peppers off aluminum trays, with metal chopsticks. Back out to the airfield, where still no one knew about any gas. Claeys kept looking down at his watch and up at the sky. You never want to "have to" make a trip in a small plane, but he felt he had to get to Zhuhai by dawn.

Five o'clock, still some remaining light -- and the first sign of hope! A delivery truck rolled up toward our airplane, with a large metal barrel in the rear. "Avgas!" the head of the Aviation Department said, in Chinese. Claeys asked him where it had come from. The story involved derelict ex-Soviet training planes that had been parked in a remote section of the airport. There was enough old gas left in their tanks to drain into the barrel. Claeys, who understood the description in Chinese (as I did not), blanched. A little later he let me know what they had said.

In pilot school, you're taught to be hyperconscious of the quality of the fuel going into the gas tank. Claeys and I rationalized that if the fuel was bad enough -- who knows how long it had been in those Soviet-airplane tanks, or where else it might have been -- the engine wouldn't start at all. And if it was good enough to get the plane through the engine start and the test runup, or trial revving of the propellers before takeoff, it would probably at least get us up to an altitude from which we could deploy the parachute if need be. This is not the way I had been taught to operate an airplane, and not what Claeys would have liked to do, but, I told myself, This is China. Meanwhile, Walter Wang was reading peacefully.

The most dangerous time in a small-plane flight is the first 30 or 40 seconds after the wheels leave the runway. If the engine fails then, because the fuel flow is obstructed or the engine hesitates when suddenly pushed to full power, you are in danger precisely because you're so close to the ground. The engine came up smoothly; the plane reached an air speed of 70 knots, at which point Claeys began easing its nose upward; at about the same time as we got a safe distance off the runway, we disappeared into the brown blear of the standard big-city Chinese pollution shroud. And we were off.

Between Changsha and Zhuhai stood the mountains of southern Hunan. They are not tremendously high by world standards, but they were higher than our airplane was at its initial assigned altitude. And unless the controller gave us instructions to climb -- as we would routinely expect a few minutes into the flight -- we would be headed for trouble soon. On the GPS-based moving map in the cockpit, we saw the ridge draw closer. We couldn't legally turn around, since that would be deviating from our clearance. Nor -- again without breaking rules -- could we decide to climb on our own. If we kept on straight and level, within ten minutes we'd crash. Then within eight minutes. Then six.