The night of/morning after.

Whatever happened just did so. No one knows what’s happening yet, and people are panicking. People are arming themselves to defend against the real threats of wild animals suddenly changed into new forms, some far more powerful than before. As well as against the imagined threats of the creatures who were once human. The average person can’t tell the difference between the two, but some creatures can talk. And some look eerily like twisted versions of friends and family who have gone missing. Few people will remember this day fondly.