We are presented with Abigail facing a very difficult and dangerous position in Act I. The apparent witchery of Betty and Ruth Putnam with which the play opens leaves her in a very vulnerable position. As she realises that her uncle has seen her dancing naked in the woods with other girls, she realises that she must embark on an excercise of damage limitation in a desperate attempt to ensure that the real truth of what she did--drinking blood as a charm to kill Goody Proctor--does not get out. Thus we see Abigail becoming increasingly desperate, in particular with the girls, as she seeks to limit what is revealed and to agree on a common story. Note the following quote:
Now look you. All of you. We danced. And Tituba conjured Ruth Putnam's dead sisters. And that is all. And mark this. Let either of you breathe a word, or the edge of a word, about the other things, and I will come to you in the black of some terrible night and I will bring a pointy reckoning that will shudder you.
Abigail's principal aim in Act One is therefore to control the situation and to prevent the full disclosure of her own activities. She is desperately trying to maintain control of a situation that seems to be running out of control, and she is willing to threaten the other girls to try and regain that control. It is interesting therefore that the subsequent witch hunt is clearly not something that Abigail planned. She is an opportunist, who desperately tries to keep up with the pace of events, and uses them to her own advantage.