The people of Salem have finally reached a point of doubt with Rev. Danforth and his panel of judges. So many people are in jail that crops are left untended and children are left orphaned. If those imprisoned continue to proclaim their innocence to the point of death, then it stands to reason that perhaps they are, indeed, innocent. Parris is desperate; he is beginning to receive death threats, and his principal witness--Abigail herself--has fled town. He asks that those remaining in prison be pardoned so he will be safe, but Danforth knows that to back down now would be to admit that the council has been wrong with their accusations all along. Instead, Danforth pushes to hurry along the executions of the most prominent citizens so far, among them Rebecca Nurse and John Proctor, if they will not confess. Rev. Hale has returned to town upon his own guilty conscience for ever having taken part in the farce. He wants John to admit to witchcraft to save his life. Danforth encourages this confession, believing John's admission will validate the deaths of those already executed. The overshadowing doubt of the townspeople, combined with the urgency felt by both Parris and Danforth, work together to push the play to its climax.
I would say that the village of Salem is very tense in the beginning of this act. You can see this in the discussion of Parris and the cows -- the town has clearly been disrupted.
I think you could say that the mood of the town makes the authorities (Danforth, especially) less likely to forgive the people who have been convicted. The authorities would be worried about the tension and they would think they need to show that they are firmly in control.
To show they are in control, they go ahead with the executions of people like Proctor and Rebecca Nurse.
In The book The Crucible Salem has become a place of desolate landscapes. Cows wander uncared for throughout the land. Farms have gone to waste. There is a sense of paranoia and hopelessness and fear. The witch trails have taken away farmers from their land, mothers from their children, and created orphans.
In the book Paris has become alarmed that if the trials continue there could be problems later. He explains that there has started to be unrest and a possibility of revolution among the citizens. Danfourth disputes his ideas and desires to continue with the trials, convictions, and punishment for the prisoners.