How does the quote "The best laid plans of mice and men often go awry" relate to a character in The Crucible?

John Proctor who, as a moral man, has  impeccable character but ends up toally broken and in chains in Miller's The Crucible because of hearsay and hysteria about wirchcraft. In the beginning, in Act 2, John tries to help those accuse. In Act 2, he enters with Mary Warren, promising to clear up any doubts regarding the girls, if his wife is freed from custody. During the ensuing conversation, Danforth reveals Elizabeth is pregnant, which catches Proctor off-guard. Danforth then orders the girls into the vestry, to test Proctor's accusations. Reverend Parris is skeptical, pointing out that the girls fainted, screamed, and turned cold before the accused, which they see as proof of the spirits. Mary tells them that she believed at first to have seen the spirits, however knows now that there aren't any.

In an attempt to discredit Mary, Abigail and the other girls begin to scream and cry out that they are freezing. When Abigail calls to God, Proctor accuses her of being a whore and tells the court of their affair. Abigail denies it and the court has Elizabeth brought in to verify if Proctor is telling the truth. Not knowing that he had already confessed, Elizabeth lies and denies any knowledge of the affair. When Proctor continues to insist that the affair took place, the girls begin to pretend to see a yellow bird sent by Mary to attack them. To save herself from being accused of witchcraft, Mary tells the court that Proctor was in league with the devil and forced her to testify. Proctor, in a fury, proclaims that "God is dead!" and is arrested for witchcraft. Reverend Hale announces, with Danforth chasing him down: "I denounce these proceedings, I QUIT THIS COURT!"

In Act 4 Proctor is chained to a jail wall totally isolated from the outside. Reverend Paris is in a panic over the upcoming executions, as John was a respected member of community (as were Martha Corey and Rebecca Nurse, who are also to be hanged) and he explains his fears to Hathorne, Danforth and Cheever. He also reveals that Abigail and Mercy Lewis (one of the "afflicted" girls) stole all of his money and boarded a ship in the night. Hale enters, now a broken man who spends all his time with the prisoners, praying with them and advising prisoners to confess to witchcraft, so that they can live. The authorities send Elizabeth to John, telling her to try to convince Proctor to confess to being a warlock. When Proctor and Elizabeth are alone, she convinces him to confess to the crime of witchcraft. John, in turn relays this to Hathorne, who is almost overjoyed to hear such news and practically screams it to the outside world: "HE WILL CONFESS". Proctor then signs the confession, then tears it up when realizing that Danforth is going to nail the signed confession to the church (which Proctor fears will ruin his name and the names of other Salemites). The play ends with Proctor and Rebecca Nurse being led to the gallows to hang as Reverend Hale makes a last-ditch effort to save his life via Elizabeth.

In this play one can see that John Proctor was vicitimized because he was trying to help people but he got dragged into the hysteria and will die. "The Best Laid Plans of Mice and Men often go awry" means that when people make plans, they often get all mixed up and go exactly the opposite which is what happened to Proctor.

This is really about the Salem Wirch Trials, you know. And, in those trials, many people were involved and everything went wrong. Alltheir plans went wrong.