Maycomb, Alabama is a quiet town where people don't lock their doors. The story begins in the 1930's, the town seems peaceful and quiet at first. The archetypes for the story are as follows: Hero: Atticus, call to adventure: Judge John Taylor choosing Atticus for the case, Threshold Guardians: Mr. Cuningham and the mob outside the jail.
Answering the Call
A black man (Tom Robinson) is accused of raping a white woman (Mayella Ewell). Judge John Taylor chooses Atticus to represent Tom Robinson in court.
Atticus is worried about what accepting the case will mean for his kids. He believes the citizens of Maycomb will take their anger out on them.
Crossing the Threshold
Atticus doesn't need to think long, he accepts. He does this because he know's his kids are tough enough to take whatever the town can throw their way. But more importantly, Atticus wouldn't be able to live with himself, never mind expect the kids to respect him, if he doesn't do what's right and stand by his beliefs. He wants to teach his kids that no matter who or what a person is, they should be seen as equal to everyone else when it comes to court.
Throughout Atticus's journey Jem and scout are always there with him and they're a big factor in Atticus taking the case.
As soon as Atticus takes the case he leaves the threshold of the ordinary world. He is no longer complacent with the unspoken rules of Maycomb society when he openly supports equal rights in the court.