Despite Jem’s disagreement, Scout says she thinks that Boo Radley is in the Radley home and watching the kids play. How does Lee foreshadow the revelation?

Lee foreshadows this revelation is a number of ways. First, through the gifts in the tree. Second, when asked to play the Boo Radley game, Scout is very unsure, she says that Boo can get out at night and is afraid they'll be harmed. Lastly, Scout hears laughter when she crashes into the Radley house in the tire..... "The first reason happened the day I rolled into the Radley front yard. Through all the head-shaking, quelling of nausea and Jem-yelling, I had heard another sound, so low I could not have heard it from the side-walk. Someone inside the house was laughing."