When Aunt Alexandra says that Ewell could do something furtive to Atticus, she means that Atticus should be very careful. She warns him that Ewell will be very secretive.
In chapter 28 of "To Kill a Mockingbird," Aunt Alexandra has a premonition about Bob Ewell seeking revenge on Atticus and his family after the trial. She worries that Bob Ewell, being humiliated by the trial's outcome, may try to harm them.
The conflict between Bob Ewell and Atticus in "To Kill a Mockingbird" mainly stems from Ewell's resentment towards Atticus for defending Tom Robinson in court. Ewell feels humiliated by the trial's outcome and takes his anger out on Atticus and his family. Atticus remains calm and tries to defuse the situation through his unwavering sense of justice and integrity.
At one point in the book, Bob Ewell spits in Atticus's face for humiliating him in court.
In the courthouse, Mr. Ewell confronted Atticus about being threatened during the trial. Atticus remained calm and assured Mr. Ewell that he had no intention of harming him. Mr. Ewell eventually left, feeling humiliated.
When Ewell was on the stand, Atticus asked him to write his name. Signing your name is a habit; you'll always use your dominant hand. Ewell complied, not realizing why Atticus asked for this.
Bob after the trial threatens Atticus that he will shoot him. Bob Ewell feels a lot of anger towards Atticus because Atticus humiliated Bob Ewell in his first time in court. Although Bob Ewell did win the case he lost a lot of his little pride he had.
Mayella Ewell wanted Atticus to dismiss Calpurnia because she felt that Calpurnia was getting too close to Tom Robinson. Mayella feared that Calpurnia would influence Atticus to see the truth of Tom's innocence.
Bob Ewell spits in Atticus' face out of spite and a desire for revenge, as he is angry that Atticus was able to prove his daughter Mayella was lying about the assault. Ewell's pride is wounded, and he seeks to humiliate Atticus as a form of retaliation.
Bob Ewell, who is Mayella's father, beat her up
Bob Ewell had falsely accused Tom Robinson of raping his daughter, Mayella Ewell, which led to Atticus defending Tom in court. This created tension and animosity towards Atticus and his family in their small town.
Bob Ewell is upset with Atticus after the verdict because Atticus has made Bob Ewell out to be a liar. Bob Ewell and Atticus are characters from the book, "To Kill a Mockingbird", by Harper Lee.
He spit in Atticus's face. And Atticus didn't fight him, he simply walked past Mr.Ewell.