In chapters 4-7 of the book "To Kill a Mockingbird," how did Jem lose his pants, and what did he discover upon returning for them?

In chapters 4-7 of "To Kill a Mockingbird," Jem loses his pants during an incident at the Radley Place, which is the home of the mysterious recluse, Boo Radley. Jem, Scout (his sister), and their friend Dill are intrigued by the Radley house and its inhabitant due to the various rumors that circulate about them. One night, they dare to sneak into the Radley's property to get a glimpse of Boo. As that happens, Jem, Scout, and Dill are startled by a shadowy figure and in their rush to escape, they cross the Radley's fence. Nathan Radley, Boo Radley's brother, hears them and comes out with a shotgun, assuming they are trespassers. Fearing they have been discovered, they scramble to escape. In the process, Jem gets caught on the fence and in his panic to free himself and flee before being discovered or shot at, he leaves his pants behind.

Jem is deeply troubled by the loss of his pants because it is physical evidence that could trace him back to the Radley place and cause trouble. Despite the risk and against Scout's advice, Jem decides later that night to return to retrieve his pants to prevent anyone from finding them and linking him to the attempted intrusion. Upon returning for his pants, he discovers that they have been mended and neatly folded on the fence, as if someone knew he would come back for them. This incident is a subtle hint that Boo Radley, who is actually watching the children with a kind and protective gaze, has taken the pants, sewn them up, and placed them for Jem to find—a sign that he means no harm and is perhaps trying to communicate or help them in his own way.