It is in Chapter 6 of Harper Lee's To Kill a Mockingbird that Jem rips and even loses his pants. On Dill's last night in Maycomb for the summer, Jem and Dill concoct a scheme to sneak onto the property of the Radley Place and to "peep in the window with the loose shutter to see if they could get a look at Boo Radley." Scout protests the wisdom of the antic but winds up coming along nonetheless.
The children decide that their best approach to getting on to the property is to sneak under the high bobbed-wire fence that "enclosed a large garden" at the back of the Radley property, near the schoolyard. The children manage to sneak through the garden, through a gate separating the garden from the Radleys' backyard, and to creep to the side of the house where the "window with the hanging shutter stood." They then give Dill a boost up to the tall windowsill so that he can take a look inside, but Dill is unable to see anything of interest. Next, they sneak on to the back porch to get a look through the back window, which is when Scout sees the shadow of a man moving "across the porch toward Jem." As the kids race away from the house, shots ring out. But, as they try to scamper back under the barbed-wire fence, Scout and Dill make it safely under, but Jem gets his pants caught in the wire and must kick them off to get free. It's at the moment that he gets his pants caught in the barbed-wire that he tears them.
More interesting than the moment he tears his pants is the moment he retrieves them. Jem decides to go back for his pants at 2 o'clock in the morning. Later, in Chapter 7, we learn that, when he went back, he found them neatly "folded across the fence" and "sewed up." Jem reaches the conclusion that Arthur (Boo) Radley mended Jem's pants for him, a conclusion that says much about the true nature of Arthur Radley. Author Lee uses the development of Arthur's character to further develop her theme concerning the falseness of prejudiced beliefs.