S.E. Hinton opens Chapter Two of Rumble Fish with foreshadowing.
Foreshadowing is a way for a writer to give a hint of things to come. It lets the writer build suspense and tease details of what might happen later in the story.
S.E. Hinton writes: "I was hanging out at Benny's, playing pool, when I heard Biff Wilcox was looking to kill me." The narrator of the story, Rusty-James, is spending time at a local hangout for junior high kids. He's warned that because of his interaction with Anita at school, Biff is now after him.
The interaction is also a callback to the beginning of the book, where the adult narrator comes across an old friend on the beach. His friend remarks on his knife scar -- the one Biff gives him in the fight they have after Rusty-James is warned about Biff's violent intentions.
S.E. Hinton uses the opening sentence of Chapter Two to foreshadow the fight with Biff. While the fight doesn't end in death, it does give the narrator a scar that lasts for the rest of his life.