Humans have been spotted, we must destroy them at once. We can't risk our artifacts falling into their hands!
We've destroyed their ship, but have taken quite a bit of damage ourselves. They're landing on a nearby planet, follow them and wipe out any survivors!
We were unable to kill the human, he has taken an escape pod back to Earth. We must find those artifacts in the ship wreckage.
First look at the other side of the story. The aliens have not forgotten how their invading force have been badly mauled and beaten single-handedly by humans. The aliens spotted a human ship in the vincity (The Echo-1), and believeing that the humans are in their sector of the galaxy to steal artifacts, they zapped the human ship, and crash-landed on an unknown planet, presumably to be Mercury.
