Bang You're Dead

This is a science fiction story of an invasion of Planet Earth. Actually, it was an accidental invasion because our alien force consisted of one single alien and a survivor of its spaceships crash. The other members of the crew were killed, and he had no way of calling for help. So, it did the only thing left for it to do, invade the planet and be the first of its kind to do it single handily It had the will, it recruited an army, but it just didn't have the resources it would require.
After the initial failure it would find itself running for its life as our hero went after it. This was a battle to the finish in a world that was more advance and more deadly than it had anticipated and so the battle went on across the land as the runner did everything it could to keep away from the pursuer only to eventually bring it all to a head. Meanwhile, the dead pile up and the movements of the alien continue to defy the federals who were after it.
This is a battle to the finish and this one lone alien would be a handful in every sense of the word. In the end it would fail in its attempt to invade, but in doing it those who survived learned that there were others out there and some of them were not friendly in the least bit.