Laurie Saunders is a senior at Gordon High School. She is popular and studious and works as editor-in-chief of the school newspaper, The Gordon Grapevine. She is frustrated because although she works hard, the rest of her staff is very lazy and the newspaper always puts out late issues. Meanwhile, Ben Ross is having similar problems. Mr. Ross is a young history teacher who is looking for ways to teach his students about World War II. He shows them a movie about the Holocaust so they will see the negative consequences of dictatorship. The students ask Mr. Ross why anyone would let the Nazis take power, but he doesn’t know himself.
Laurie is in Mr. Ross’s history class and she was deeply disturbed by the movie’s graphic images of suffering and murder. She goes to lunch with her boyfriend, David Collins (who is also a runningback on the football team), and her best friend Amy Smith, and a few other people. No one was as disturbed by the movie as Laurie was. She and David discuss how Robert Billings, ‘the class loser,’ always eats lunch by himself.
At home, Mr. Ross devises an experiment to show his students what life was like under the Nazis. He discusses it with his wife, Christy. The next day, he introduces the students to the concept of “Strength Through Discipline.” He explains that they can make their lives better if they live in a more organized and disciplined fashion. He gives the class a posture lesson and insists that they stand up and address him as “Mr. Ross” when they are answering questions. Robert is very excited about the new routine even though he is usually a bad student.
The next day, Mr. Ross is impressed that the students remembered his lesson about discipline and are still excited about it. He adds to the lesson, adding the concept of “Strength Through Community.” In his class, everyone is equal and the students are responsible for helping each other. He calls this The Wave and teaches the students a salute that they can use with each other. David admires Mr. Ross’s ideas and teaches them to the football team, which always loses its games because the players don’t show up to practices.
At home, Mr. Ross devotes more and more time to planning The Wave, something that upsets Christy. Meanwhile, Laurie tells her parents about The Wave. Her mother warns her that The Wave might have negative consequences for those who don’t fit in, and she should always try to think for herself.
On Wednesday, Mr. Ross introduces The Wave’s final motto: “Strength Through Action.” He also encourages the students to recruit people outside the class to join The Wave. At lunch, all the students in The Wave sit together rather than breaking into separate cliques. Laurie notices that for the first time, Robert is included and treated like an equal part of the group. However, she voices concerns that The Wave is a little weird. No one agrees with her.
Mr. Ross is called to the principal’s office. Principal Owens approves of The Wave, but he becomes skeptical when he learns it’s an experiment to teach students about Nazi Germany. However, Mr. Ross reassures him that the project will teach the students a valuable lesson. At the publications office, Laurie finds an anonymous note addressed to The Grapevine. It is from a student who describes his experiences being bullied because he did not want to join The Wave. Meanwhile, Mr. Ross notices that students are becoming ever more enthusiastic about the movement, making posters and handing out pamphlets without any instructions from him. He also notices Robert following him around. When Mr. Ross asks Robert what he is doing, Robert explains that he wants to be Mr. Ross’s bodyguard. The teacher reluctantly agrees.
Laurie hears a fight in the Quad. It is between Brian Ammon and Deutsch, two rivals on the football team. As Principal Owens breaks up the fight, Brian yells out some Wave slogans on his way to the principal’s office. This disturbs Laurie, but David reassures her that Brian and Deutsch were rivals anyway and The Wave is still a good thing. He is offended when she says she does not want to attend a rally for The Wave, which is scheduled for Friday. They have a fight and David breaks up with her.
Laurie skips the rally and confides in her friends Carl Block and Alex Cooper, two jokesters from the newspaper who have never liked The Wave. They decide to publish a special issue of The Grapevine that will expose the problems with the new movement. That night, Laurie’s father tells her about rumors that a sophomore was beaten up for not being part of The Wave. He adds that the sophomore’s attackers called him a ‘dirty Jew.’
When she tries to attend a big football game the next day, Laurie is surprised to find that she cannot enter the stands without giving the Wave salute. Brad, the boy guarding the entrance to the stands, seems afraid to not enforce the rules, so she storms off angrily. At her house, several staff members of the newspaper put together a special issue of The Grapevine. It includes a report on the student who was beaten and editorial critical of The Wave. When Laurie shows the editorial to Amy before it is published, Amy is furious at her.
However, the newspaper makes some students more comfortable about speaking out against The Wave. Many of them reject The Wave since it did not help the football team win its big game against Clarksville. Mr. Ross notices that the other teachers seem to have turned against The Wave, something that is confirmed when Christy and Principal Owens confront him about it. However, he reassures his wife and boss that he has a plan to end the experiment gracefully, in a way that will teach the students about fascism. They agree, although Principal Owens threatens to fire Mr. Ross if the experiment continues to go awry.
Laurie leaves school late. She notices that someone has scrawled the word “enemy” on her locker, presumably because of her involvement with the newspaper’s editorial. After being urged by his friends, David confronts her and asks her not to write any more articles critical of The Wave. They argue, and David pushes her to the ground. When he realizes that The Wave has inspired him to be violent with his girlfriend, he renounces the movement and reconciles with Laurie. They go to Mr. Ross’s house to ask him to stop The Wave. He agrees.
The next day, Mr. Ross informs the students that The Wave is part of a national political movement, and invites them to a rally where they will hear a televised address from the movement’s leader. David and Laurie try to object to this, but Mr. Ross sends them to the principal’s office. Both Mr. Ross and Principal Owens urge them to hold their criticisms and wait to see what happens at the rally.
At the rally, Mr. Ross shows the enthusiastic students footage of Hitler. He explains that this is their leader, and they would all have been good Nazis if they had lived in the 1930s. He urges them to think critically and to stand up for themselves rather than submitting mindlessly to the group. He then shows footage from the concentration camp documentary. The students are stunned and feel guilty about their involvement in The Wave. Laurie and David approach Mr. Ross after the rally and thank him for the lesson. He apologizes to them that The Wave got out of hand. As they leave, Mr. Ross notices Robert crying in the corner. He invites Robert out to lunch, where they will discuss The Wave and how Robert can find a healthy way to turn his life around.