Jem cries when Nathan Radley cements over the knot hole.
Jem is a character of the novel to kill a mockingbird who ages from 10 to 13 over the course of the story.
Jem represents the idea of bravery in the novel, and the way that his definition shifts over the course of the story is important. The changes he undergoes are seen from the point-of-view of a younger sister.