How do we learn what has changed in Salem between Acts I and II in The Crucible?
In Act II of The Crucible, we learn that the town of Salem has changed quickly in the eight days since Act I through the words of Mary Warren and Elizabeth Proctor. Mary Warren comes from town, and it is through her dialogue, as well as previous discussions she has had with Elizabeth, that we learn about the town's changes.
Since the accusations of witchcraft began in Parris' house, a court has been formed to seek out and try witches. While John, knowing that the girls are faking, believes nothing will come of it, Elizabeth knows better. She has spoken with Mary Warren and tells her husband, "There be fourteen people in the jail now, she says. And they’ll be tried, and the court have power to hang them too." Elizabeth reports that Abigail seems to be in the center of the storm as people look to her to place blame on suspected witches in the town.
The normally levelheaded town has been quickly caught up in the hysteria. When Mary Warren returns, she reports that Goody Osburn will hang for her supposed crime. Since she will not confess, the court has decided that she is guilty. This only foreshadows darker times ahead for the people of Salem.