What happens to Governor Adros when he arrives to take the charter in the book The Witch of Blackbird Pond?
I would not say that anything actually happens to Governor Adros when he arrives to take the charter. In the chapter before his arrival, the reader is told that the townspeople know that Adros is on his way to their town to take over the charter. Most of the people are not excited about that. They want to rule themselves, which is a popular colonial attitude at the time, especially in the Witch of Blackbird Pond's case since the Wood family plays a prominent role and is definitely not in favor of British rule.
The townspeople meet and debate what to do about the incoming governor. A few suggest violence, which does not happen.
What does happen is that Adros does arrive, is not given a warm welcome, and attends some meetings with the townspeople and "higher ups." During those meetings William Ashby steals the charter and hides it. Ashby remains fairly calm that the charter "mysteriously disappeared" and knows realistically that it won't be found.