Jem, Scout, and Dill spend their summers engaged in imaginary reenactments and speculations, mischievous and playful acts, and real experiences.

• Imaginary re-enactments

After the Finch children meet Charles Baker Harris (Dill)--"a pocket Merlin," as Scout refers to him--whose creative imagination knows no bounds, the children re-enact dramas together. Dill is able to effectively play the roles of

...the ape in Tarzan, Mr. Crabtree in The Rover Boys, and Mr. Damon in Tom Swift. 

• Speculations

Fascinated by the Radley place, Dill wonders about the recluse who resides inside the dilapidated house. According to "neighborhood legend" the occupant, known as Boo Radley, possesses a questionable past because he associated as a youth with the Old Sarum group, who were considered the closest thing to a gang that Maycomb possessed. When he was involved with this group who was apprehended by the law, the others went to the reform school, but Mr. Radley insisted that Arthur be jailed locally. Later, Mr. Radley more or less locked Arthur up in their own home after he was told that his son could not remain confined in the basement of the jail (so he would be separated from the black inmates) indefinitely.

This strange history sparks the imagination of Dill, who becomes curious about what transpires inside the Radley house that has held Boo captive for so many years. "Let's make him come out," Dill suggests. From then on, Dill orchestrates actions to induce Boo to reveal himself.

• Mischievous and playful acts

During the following summer when Dill returns to Maycomb to stay with his Aunt Rachel, he devises more activities for the children. One day the children play with an old tire. After Scout "folds" herself inside it, the boys send her rolling so quickly that she turns over in front of the Radley steps. Frightened, she hurries to the safety of her yard.

Dill's curiosity about the Radleys waxes until he has Jem and Scout engaged in playing the roles of Boo and Mrs. Radley respectively while he has the role of Mr. Radley. They enact scene after scene.

He [Dill] was as good as his worst performance; his worst performance was Gothic.

Finally, the children become so engrossed in their continuing drama that they do not notice Atticus standing on the sidewalk watching them as they enact "Chapter XXV, Book II of One Man's Family." Mr. Finch soon questions the children about their performances.

• Real experiences

When Scout rolls in the tire near the Radley steps, she hears someone inside the house laughing. This experience, along with the questioning of her father regarding their dramatic performances, frightens Scout into believing that Atticus knows what they have been doing. She urges Jem to consider their actions until he finally "slowed down the game for a while."

In the meantime, Dill and Jem spend time in the treehouse "plotting and planning" while Scout occupies herself at Miss Maudie's house for the remainder of the summer, talking with her and assisting in the eradication of nut grass.

While she sits on the porch with Miss Maudie, Scout asks her about Arthur Radley and learns more about him and his family.

Later on, Jem and Dill continue their pursuit of Boo as Dill dares Jem to peep in the window of the Radley house with the loose shutter. After a fearful Jem builds up the courage to do this, Scout sees the shadow of a man who wears a hat. Then, this shadow walks around Jem, and after he passes, Jem leaps off the porch and Scout and Dill flee, also. As she and Dill and Jem run through a collard patch, they hear the roar of a shotgun. Jem hurriedly urges them to go through the fence by the schoolyard where they can hide behind a big oak tree. But after crawling through the wire fence that Jem holds for them, Dill and Scout soon realize that her brother is not following them. They sprint back to the wire fence and see Jem hurrying to the oak tree in his undershorts because his pants were caught on the wire.

Of course, the shotgun blast has awakened the entire neighborhood. Miss Maudie tells the children that Mr. Radley shot at a Negro in his collard patch:

"Shot in the air. Scared him pale, though. Says he's got the other barrel waitin' for the next sound he hears in that patch, an' next time he won't aim high, be it dog, n****r, or--Jem Finch!"

Not long after this incident, Dill returns to Mississippi and the children go back to school.

The following summer, Dill does not show up in Maycomb because his mother has remarried. However, when his mother becomes preoccupied with her new husband, Dill is so neglected that he runs away, and Scout finds him hiding under her bed one night. Jem reports Dill to his father, who contacts Miss Rachel.

So, Dill gets to stay in Maycomb, and the children, who one day overhear Sheriff Tate tell Atticus that rape suspect Tom Robinson has been moved to the city jail. So, when Atticus is overheard saying he may be home late, Jem decides to seek him, and the other children follow along. As it turns out, the children's disobedience saves Atticus from the mob's harm since Mr. Cunningham, to whom Scout speaks, feels a twinge of conscience and turns the mob around; then, they depart.

Further, in this summer of the trial of Tom Robinson, the children are introduced to the cruel world of adults, and they mature in thought. Dill especially is affected by the experience of witnessing the injustice of men.