Hmm, well, in the late 1300's there could be a possible alien encounter.
I have an idea, but it's rather disturbing.
Perhaps an alien race, believed to only be a legend or frightening rumor to Ten's knowledge, has decided to harvest the human corpses left over from the Black Plague?
They can be a type of alien that consumes the flesh off humans. My character can be a healer, attempting to treat those who are still suffering aliments from the plague and other diseases. However sometimes she must discard the bodies of which the souls have left. During the transportation of a few corpses for burial rights, she discovers (what looks like) deformed, psychopathic humans feasting on the remains of deceased people.
My character panics, spreading word to the officials of the horrors she has witnessed. Sadly, the town dismisses her stories. Unable to fathom such a reality. Maybe my character can be trying to solve this mystery herself, while still attending to the sickly as well. She seeks out information, studies the behaviors of these unknown creatures and documents their movements for research. Unfortunately, the town begins to question her sanity.
She is ostracized by her own community, having been deemed insane. The aliens continue to gorge themselves with human flesh. Men, women, children...they have no preference. My character shelters her sickly, trying to protect them from death since she knows what awaits them after wards. She lives each night in constant fear that those creatures might invade the town and begin consuming flesh from the living.
Just a suggestion, of course.