Un groupe d'ados rêve d'un avenir meilleur. Leur leader, un nouvel étudiant, recrute quatre outsiders pour mener le combat, mais la situation dégénère rapidement.

Tristan defends his friends when the school's neo-Nazi contingent attacks them during a weekend hangout, while Lea breaks away from her former circle.

After their protests go viral on social media, Lea pressures Tristan to allow more members into the Wave, but the movement escalates uncontrollably.

After a poorly planned raid on a slaughterhouse, the Wave spins out of control and a rift develops between Lea and Tristan that tears the group apart.

The original five members of the Wave reunite and take action against a right-wing politician and an SUV dealership, but the authorities close in.

After blood is shed for the movement, the Wave's remaining members plan a new action that crosses the line between peaceful protest and violence.