Each episode follows a main plot. Mater is spending a regular day in Radiator Springs, until he gets called on a secret mission. An alarm light would appear from the ground, and then Mater would get sent somewhere. At the place he gets sent to, Finn McMissile, Holley Shiftwell, and a Secret Spy Screen are there. The Secret Spy Screen tells Mater that Grem and Acer are up to something, and that he must stop them. A bunch of robotic arms suit up Mater, and Mater gets sent back to Radiator Springs for his mission.
Mater finds Grem and Acer, and they get into a fight. Mater defeats Grem and Acer by using one of his gadgets to destroy Grem and Acer into a bunch of bricks. However, Mater gets into another problem.