The snowmen made by people in the city suddenly began to move and attack, some of them becoming quite large in the process. They appeared to be powered by black stones of some sort, though who might have placed them, I cannot say.

[She's merely grateful she was able to discern their weakness before they overwhelmed her and her companions.]

The ones in charge--in particular, the priestess Rhea--say it is a mystery to them as well. I'm not certain they are completely unaware of their origins, though I do believe they were not involved.