There is evidence in Act I that hints at what is to come in Act II. In Act I, the reader learns that John Proctor had an affair with Abigail, additionally we learn that she is still very much in love with him. She wants him, and she wants his wife out of the way.
So right here, we know that if she gets an opening, she will find a way to get rid of Elizabeth. At the end of Act I, when Abigail confesses to witchcraft and then begs for mercy, becoming a star witness for the court to prosecute anyone that she names as being guilty of witchcraft, she has an opportunity to get rid of Elizabeth Proctor.
In Act II, when Mary Warren comes home and tells the Proctors that Elizabeth's name was mentioned in court, it is evidence that it won't be long before Elizabeth is arrested. Elizabeth is arrested at the end of Act II, taken away in chains for a cime that she did not commit.
Act II, also at the end, John Proctor says that he will fall like an ocean on the court the next day. So there is an indication that Proctor will be going to court with the intention of making the truth known.
The reader knows by now that the truth doesn't matter to the court. They are creating the truth based on the allegations of the girls who are now looked upon as authorities on witchcraft, they are able to identify witches. And they name anyone they want revenge or retribution against.