For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Luckily for you, Shmoopers, Don DeLillo had the good sense to divide this book into three main parts, which makes the whole Three Act Plot Analysis thing easy-peasy. The first act (or section) of this book is titled "Waves and Radiation," and it's almost entirely expository. In it, you have scenes of Jack Gladney (the protagonist) and his family arguing in the kitchen, cruising through the supermarket, and settling in for some Friday night TV.
Throughout these scenes, DeLillo gives us several seminars on modern American culture. We also get to meet Jack's friend Murray Siskind, a former sportswriter from New York who's even kookier than Jack.
Act II
DeLillo names Act II of his novel "The Airborne Toxic Event," after the chemical spill that creates a massive cloud of noxious gas over Jack's neighborhood. Jack isn't concerned about the cloud at first. But after exposing himself directly to the "event," Jack learns that he's going to die at some unknown point in the future, probably within thirty years. But since Jack is in his mid-fifties anyhow (and this novel takes place in 1985, when life expectancies were shorter), it shouldn't exactly be breaking news that he'll kick the bucket before eighty-five.
The funny thing about his situation is that everyone knows they're going to die at some unknown point in the future. The fact that a poisonous chemical has confirmed this for Jack is a little redundant, but that doesn't stop Jack from becoming obsessively terrified about when he's going to die.
Act III
In Act III, titled "Dylarama," Jack finds out that his wife, Babette, has become addicted to an experimental drug called Dylar. Worse yet, Babette has become so desperate for Dylar that she's traded sex to get it. Jack is obsessed with the thought of death, and he wants some of this Dylar for himself.
He also wants to kill the man behind this drug for sleeping with his wife. After some amateur sleuthing, Jack tracks down his enemy—a man named Willie Mink—and shoots him through the gut. After the initial thrill of shooting him wears off, though, Jack takes Willie to the hospital, where the man survives.
In the book's final scene, we watch Babette's youngest son, Wilder, travel across a busy highway on his tricycle, completely oblivious to how close he is to dying. With this final scene, Jack meditates about how differently adults and children approach the idea of death.