Scout runs to her father as he faces the group of men outside of the jail. She expects him to be happy to see her, but what is Atticus’s reaction?

In Chapter 15, we learn that Tom Robinson has been moved to the Maycomb jail.

One Sunday night after dinner, Atticus announces that he will need to go out. Suspicious, both Jem and Scout decide to follow him after he leaves. They pick up Dill along the way and go by Atticus' office at the courthouse. However, he isn't there. The children then decide to see if Atticus is with Mr. Underwood at the Maycomb...

In Chapter 15, we learn that Tom Robinson has been moved to the Maycomb jail.

One Sunday night after dinner, Atticus announces that he will need to go out. Suspicious, both Jem and Scout decide to follow him after he leaves. They pick up Dill along the way and go by Atticus' office at the courthouse. However, he isn't there. The children then decide to see if Atticus is with Mr. Underwood at the Maycomb Tribune office. In order to reach the Tribune office, the trio will need to pass by the county jail.

As they walk past, they notice a curious sight: Atticus is sitting right outside the jail, propped against the front door. As they approach, he is reading and does not notice the children. In due time, four cars drive up and men get out to walk to where Atticus is sitting. Ominously, they ask if Tom Robinson is inside the prison. Atticus knows that they want to lynch Tom, and he quietly orders all the men to go back to where they came from.

It's at this very moment that Scout breaks away from Dill and Jem to run towards Atticus. Thinking that her father would be happy to see her, she is frightened when she sees the fear in Atticus' eyes. The fact of the matter is that the men have come to do violence, and Atticus is afraid that his own children might get hurt in any ensuing mayhem.

We know that Atticus is afraid because his fingers are trembling slightly when he puts his newspaper down; as calmly as he can, Atticus tries to order Jem to take Scout and Dill home. However, Jem remains stubborn; he knows that something is wrong, and he will not desert his own father at such a moment. The men grow restless and demand that the children be removed from the premises.

Someone grabs Jem to pull him away, but Scout kicks the perpetrator in response. Atticus tries to calm everyone down but is only marginally successful. It is Scout who saves the day, however, when she greets Walter Cunningham. With her friendly greeting and kind conversation, she is able to do what no one else can: she so disarms the men that Walter Cunningham eventually orders his men to go home.