Fall comes to Sequoia and with it, the California wildfires. While the entire community fights to save their town, Zion and Tate get swept up in a new mystery. Zephyr's uncle discovers a dead body in a burnt-out shack, claiming he's found proof that Sequoia is being invaded by aliens. Unfortunately, Sheriff Wilson has other ideas about the man's death, forcing Tate and Zion to open an investigation in order to save Alvin O'Malley. Can they...