I was an enlisted grunt in a mercenary force on a distant alien world. We were fighting the natives in a gruesome war of suppression. Our division was marching to certain death, and I knew it, so I deserted. From a nearby hill, I watched as an enemy ship-- huge, elongated, shaped vaguely like an aerobic weight-- descended upon my former army pals and irradiated them, killing them all instantly. I alone was alive.
It was up to me to finish our mission, whatever it was.
But by this time I realized I was being tailed by assassins from my own unit, who were going to execute me for desertion. I began to run, but was captured by a native. He could move silently over the normally-loud terrain of crackly dry leaves and sticks. He was a farmer and a herder; he put me in a pen with his livestock. They seemed hostile at first, but then it turned out they were both intelligent and friendly, to the point that they were willing to protect me against the threats of the assassins and the farmer.