In Act 2, scene I, it is revealed that Mary Warren is now an official of the court. She has gone from a meek and timid character to a defiant and important character. Because of this newly acquired power, in Act 2, scene II, Mary Warren feels justified in talking back to her employers, John and Elizabeth Proctor. She tells them that 39 people are arrested and Sarah Osburn will be hanged while Sarah Good will not because she is said to be pregnant. Mary also informs the Proctors that she will be gone everyday to court in order to do her "important" work.
The last thing that she reveals is that she saved Elizabeth's life today. Elizabeth has been accused of witchcraft, and Mary informs them that she spoke on her behalf in order to save Elizabeth's life.
Mary Warren brings home first-hand accounts of what has been going on in the courts for the past few weeks. When we last left the girls, they had just hysterically started calling out random names of women who they claimed had bewitched them, in order to get out of being held responsible for dancing in the forest. But, as Mary Warren, in Act Two, returns home from the courts where she is an "official," we see just how far things have gotten. Mary reveals two key--and terrifying--pieces of information.
1. She reveals that not only are people accused of witchcraft, the courts are actually going to go through with hanging some of them. One of the first: Goody Osburn. Mary exlaims, in distress, that "Goody Osburn--will hang!" and goes on to tell how she herself was responsible, in part, for the verdict. This bit of information is scary because it reveals that the courts are willing to hang people, AND that they are willing to hang people on the hysterical and very non-concrete "evidence" of a young girl.
2. The most terrifying bit of news is that Mary mentions that Elizabeth had been "somewhat mentioned" in the courts. This means that Elizabeth's name had been brought up--someone there had accused Elizabeth of witchcraft. Mary says that she stepped in and "saved her life" by saying that Elizabeth was a good woman. If Elizabeth was mentioned, it is only a matter of time before she will be brought to court, and condemned as being a witch. This terrifies both John and Elizabeth, and Elizabeth correctly concludes that Abby is behind the accusation.
I hope that those thoughts help a bit; good luck!