Originally, John went to the courts in an attempt to help save his wife and friends. This leads to a long list of disappointments. First, the people who signed a petition attesting to the good names of women arrested were themselves arrested for questioning. Then his friend Giles is arrested for being in contempt of court, after he had tried to refute the Putnams. John then has to rely on Mary Warren to be brave enough to face the vindictive girls and declare them frauds. When she starts to quaver because Abby acts bewitched, John puts all of his cards on the table and confesses his affair with Abby: "I have known her sir, I have known her." But then even this doesn't work as Elizabeth-understandably-lies about the affair.
Finally, his last hope, Mary, cowardly turns on him (so the girls will stop pretending she's bewitching them), and calls him a "Devil's man" who had forced her to come overthrow the courts. Danforth immediately believes her and asks Proctor, "You are combined with anti-Christ are you not?...What say you mister?" John realizes the grave absurdity of the situation, and cries from the depths of his soul, "God is dead!" He is then arrested.
First, Proctor comes to the court with Marry Warren to prove the girls are lying. He soon later confesses his affair with Abigail and accuses her of being motivated by jealousy of his wife. Meanwhile, Abigail and the girls pretend that Mary is bewitching them, and Mary breaks down and accuses Proctor of being a witch.