ATTICUS.  Atticus has given up the gun and carefully protected his secret about being the best marksman in the county from his children. But when the mad dog appears, and Sheriff Tate "almost threw the rifle at Atticus,"

... Jem and I watched our father take the gun and walk out into the middle of the street...
     With movements so swift they seemed simultaneous, Atticus's hand yanked a ball-tipped lever as he brought the gun to his shoulder.  (Chapter 10)

JEM.  Jem isn't sure why Atticus is being confronted by the gang at the jail, but he senses that his father needs his help.

... Jem was not thinking of budging.
     "Go home, I said."
     Jem shook his head... Mutual defiance made them alike.  (Chapter 15)

SCOUT.  Scout is not impressed with the "ladies" of the Missionary Circle, but after learning of Tom Robinson's death and seeing how Miss Maudie and Aunt Alexandra react, Scout suddenly makes a stunning transformation.

     After all, if Aunty could be a lady at a time like this, so could I.  (Chapter 24)

BOO RADLEY.  Boo gives up the safety of his home to courageously rescue Jem and Scout from the murderous hands of Bob Ewell. He proves he is not a ghoul, but a hero. According to Sheriff Tate,

     "I never heard tell that it's against the law for a citizen to do his utmost to prevent a crime from being committed, which is exactly what he did... the one man who's done you and this town a great service... (Chapter 30)

DICK AVERY.  Mr. Avery is best known for his close kinship to Miss Stephanie; he, too, is a gossip who scolds the children without good reason. But on the night of Miss Maudie's housefire, Avery unexpectedly turns courageous. After everyone has left the burninghouse for the safety of the street below, Avery

... appeared in an upstairs window. He pushed a mattress out the window into the street and threw down furniture until men shouted, "Come down from there, Dick! The stairs are going! Get outta there, Mr. Avery!"  (Chapter 8)

COUSIN FRANCIS.  Scout's obnoxious cousin loves to run his mouth, but when he goes too far and feels threatened by Scout, he seeks out the safety of Alexandra's skirts. He is a coward who runs and hides when he deliberately angers Scout, baiting her by calling her "nigger-lover."

He jumped into the yard and kept his distance...
... looked at me carefully, concluded that I had been sufficiently subdued...
     This time I split my knuckle to the bone on his front teeth...
     Aunt Alexandra ministered to Francis, wiping his tears away with her handkerchief, rubbing his hair, patting his cheek.  (Chapter 9)