In To Kill a Mockingbird, Jem and Scout live in Maycomb County with their father Atticus Finch. They first meet Dill, whose real name is Charles Baker Harris, when he visits his aunt Rachel, their neighbor, for the Summer holidays and continues to visit every Summer. He is a year older than Scout and they three become firm friends.
Jem and Scout relate stories about the Radley place after it sparks Dill's imagination. Atticus won't tell them anything about the Radleys so they get all their information from another neighbor, Miss Stephanie, who confirms the anti-social nature of the Radley family who never bonded with the community and were always seen as strange. Boo Radley hasn't been seen out, in daylight, for many years after getting involved with the wrong crowd as a teenager whereafter his father locked him in the house. This is what started the problems for the Radleys. The rumor has it that, at one point, whilst confined to his home, Boo stabbed his father, in the leg, with a pair of scissors but, rather than send him away, his father kept him in the house indefinitely. Even after his father died, Boo still remained indoors and his brother came to the house and assumed his father's responsibilities.
There are therefore, many stories about Boo Radley and how he sneaks around outside at night. The children are both fascinated and terrified by their perception of Boo. Dill is determined to force Boo out of his house so he dares Jem to go into the Radley yard. Dill is convinced that Jem will not get past the gate. Jem thinks about it and not wanting to turn down a dare, he decides to do it and runs in and touches the house.