In Chapter 4 of Harper Lee's To Kill a Mockingbird, the day that Dill returns to spend his second summer in Maycomb, Scout, Dill, and Jem begin their summer by conversing about supernatural myths, which leads to Scout saying something that angers Jem.
The subject of conversation particularly turns to death and Hot Steams. When asked, Jem explains to Dill that a Hot Steam is a patch of warmth on a "lonesome road" that is actually the soul of a person "who can't get to heaven." Jem further expounds that "if you walk through him, when you die you'll be one too, an' you'll go around at night suckin' people's breath--." Jem continues to have fun spooking Dill by also disclosing that if you have to walk through a Hot Steam, you chant, "Angel-bright, life-in-death; get off the road, don't suck my breath," in order to keep the spirit at bay. At this point in the conversation, Scout stops Jem from further spooking Dill by warning Dill not to believe anything Jem is saying, stating, "Calpurnia says that's nigger-talk."
Jem scowls at Scout, which is the first point of evidence proving Jem had been angered by Scout calling his myth "nigger-talk." But, Scout doesn't realize Jem was angered until they begin playing with the old tire. It's Scout's idea to roll around in the tire, and when Jem pushes Scout in the tire "down the sidewalk with all the force of his body," Scout finally realizes just how angry she had made Jem. The tire is moving so fast that she is unable to stop it. The tire rolls right down the sidewalk to the porch of the Radley Place, where it finally comes to a stop, dumping a "dizzy and nauseated" Scout onto the walkway leading up to the house.