In the town of Salem, teenage girls, led by Abigail Williams, accuse women and men of witchcraft. One man, John Proctor, had an affair with Abigail, and he now thinks that Abigail is causing trouble because she is jealous of his wife. The efforts of the court to find out the truth are swayed by the hysteria that the girls create in the court room. The judge chooses to believe the girls' stories, to save the reputation of the court, and many innocent townspeople are executed, including John Proctor.
The play begins with Reverend Parris praying over his daughter, Betty, who lies unconscious on her bed. Reverend Parris questions his niece, Abigail Williams, and several girls about what has happened. We learn that the girls were all involved in activities in the forest led by Tituba, Parris's black slave from Barbados. Parris had discovered them and startled them so much that Betty collapsed and has not recovered.
Rumours of what has happened spread through the town and a crowd gathers downstairs in Parris's home. Among them are Thomas Putnam and his wife, who are not loyal followers of Reverend Parris. This is because Parris got the job of reverend in place of their relative. The Putnams are very concerned for their own sickly daughter and the earlier deaths of seven of their babies.
The Putnams are the first to openly suggest that the town is afflicted by witchcraft (which was thought of at the time almost as we might think of an infectious disease nowadays, but worse!). They want Parris to root out the witches within the community. Parris sends for a local expert, Reverend Hale, then questions Abigail about the events that took place in the forest, but she admits to doing nothing more than dancing.