On an otherwise typical day at Gordon High School, history teacher Mr. Ross shows his students a film about the Holocaust, displaying horrific scenes of starved, tortured, and killed prisoners inside Nazi concentration camps. Students watch in shock, though the film’s lasting impact varies. David Collins, the football team’s running back, naively believes the Holocaust was merely a part of history and that its crimes could never occur again. However, Laurie Saunders, editor-in-chief of the school newspaper and David’s girlfriend, is deeply troubled and insists the film and its history can’t be forgotten. For most students, the film and Mr. Ross’s accompanying lesson on fascism in post-World War I Germany spawn questions about how the Holocaust was allowed to happen. Students question how so many Germans gave in to the Nazis’ will, turned their eyes from or participated in such heinous crimes, and later pretended they didn’t know such horrible events occurred. Despite Mr. Ross’s talents as a teacher, however, he’s unable to provide any real answers. He then conceives a classroom “experiment” to simulate life in Nazi Germany, believing real-life experience will be the only way students can find answers to such critical questions. 

In history class the next day, Mr. Ross writes “STRENGTH THROUGH DISCIPLINE” on the blackboard. He then introduces strict speaking rules and, similar to a military leader, has students practice returning to their seats in a disciplined, unified manner. Students are immediately receptive to Mr. Ross’s militaristic exercises and the next day appear eager for more orders. His experiment then morphs into a full-blown movement called The Wave. To its motto, Mr. Ross adds the words “Community,” saying that all members must work together and be treated as equals, and later, he adds the word “Action.” He also creates a symbol for the movement, along with exclusive membership cards and a salute, then appoints several monitors to keep an eye out for dissenters. Soon, The Wave swells throughout Gordon High, with many students fully embracing the movement’s promises of power, community, and equality. Meanwhile, many of The Wave’s members also undergo significant transformations. David, for example, emerges as one of its chief supporters, enthusiastically introducing its principles to the school’s woeful football team. Robert Billings, a former target of frequent bullying, rises as one of The Wave’s most prominent figures and most zealous defenders. 

As The Wave gains momentum, though, more savvy characters see through its false promises. Bright and politically astute, Laurie’s mother, Mrs. Saunders, detects fascistic, cult-like tendencies in The Wave. Mrs. Saunders also worries that Mr. Ross is manipulating students and criticizes the movement for infringing on individualism and individual rights. Her concerns sow seeds of doubt in Laurie, who soon rises as a voice of conscience, questioning her peers’ increasingly fascistic behavior. Laurie’s concerns grow when she receives an anonymous letter at the newspaper’s office, written by a junior who was threatened by a senior for not wanting to join The Wave, and later when a Jewish sophomore is beaten up at school. 

Laurie teams up with reporters Carl Block and Alex Cooper to publish a special edition of the school paper to expose the truths about The Wave. As a result, many Wave members defect and similar stories of abuse emerge, but the exposé also fuels flames of fanaticism in the movement’s most ardent supporters. Robert and Brian Ammon, the school’s quarterback, tell David that Laurie must be silenced, and that night, after Laurie escapes an attempted attack at school, David confronts her and demands she stop speaking out against The Wave. When David throws Laurie to the ground, though, he suddenly sees how blind he’s been, and all the harm The Wave has caused. The couple then visits Mr. Ross’s house, insisting he end the movement.

Although Mr. Ross was seduced by power from the start and overlooked serious warning signs that his experiment had gone too far, he’s now fully aware that The Wave must end. Still, Mr. Ross believes that for all of Gordon High’s students to learn the lessons he intended to teach, he must see his experiment through to a powerful conclusion. The next day, the school’s principal, Mr. Owens, agrees with Mr. Ross’s plan. That day, Mr. Ross tells students The Wave isn’t merely a classroom lesson, but a nationwide movement to create a youth brigade, one that’s desperately needed to fix all that currently ails the United States. Students later gather at an assembly, where Mr. Ross promises the movement’s leader will be revealed. In stunning climax of The Wave, Alex and Carl help Mr. Ross display a giant image of Adolf Hitler. Instantly shocked and deflated, students see how they were fooled by, and complicit in, a fascistic, totalitarian movement that resembles Nazism. Mr. Ross then scolds students, and himself, for all that transpired. He knows, though, that however difficult its lessons, his experiment titled “The Wave” was needed for students to find answers to their original questions about how the Holocaust could have occurred, answers that will ultimately help them prevent its crimes from repeating.