In Harper Lee's To Kill a Mockingbird, in Chapter Six, Jem, Scout and Dill almost get caught trespassing on the Radley property. As they run away, Mr. Radley fires a gun into the air, and the children believe they are running as if their lives depended on it. They go under a fence that borders with the school yard, but Jem's pants get caught and he has to leave them there. There is no time to untangle them because they are worried that they are being pursued.
When the kids return home, excuses are made to the adults about Jem's missing pants, as everyone stand around discussing the "excitement" at the Radley place. When Jem and Scout go to bed that night, Jem tell Scout he must go back after the pants. Scout is frightened for him, especially because of Mr. Radley's gun; she even threatens to tell Atticus, but Jem explains that is has been a long time since he got in trouble with Atticus, and he doesn't want that to change. So Scout nervously waits at home until Jem returns with the pants and silently goes to bed.
In Chapter Seven, Jem tells Scout the circumstances surrounding his retrieval of the pants: when Jem got there, the pants were folded neatly on the fence, and the tear had been mended, as if a child had sewn the torn fabric back together.
'...they were folded across the fence...like they were expectin' me.'
The entire incident troubles Jem, and he shudders as he tells his sister, wondering who could have known he would be coming back for the trousers.
The children finally screwed up their courage to make a night raid on the Radley house in Chapter 6. After reaching as far as the porch, a shadow was spotted, and Jem huddled in fear as he waited to be eaten, beaten or even worse. But the shadow disappeared, and the children frantically ran home. In the process, Jem's pants became snagged on the barbed-wire fence, and he took them off, leaving them behind. Later that night, he went back to retrieve them. It was not until the next chapter that he told Scout the whole story. When he returned for his pants, he found them folded across the fence--and the tear from the fence already sewn up.
When he went to get back his pants his pants were on the fence waiting for him all nice and tidy. he said that as if Boo knew that he was going to come back and get his pants.