I don't know if this is good but heres what I put.
The story is mysterious because of the strange creatures flying around. The strange creatures were dragons, and they were repopulating quickly! But how? Where did they come from? Proof of this from the text is, "At first there were only a few, but in a week or two the country was simply running alive with dragons of all sizes, and in the air you could sometimes see them as thick as a swarm of bees."
