Michael K. seeks out the help of fellow fifth graders when the SPHDZ, who are trying to blend into Earth culture, draw attention to themselves by mixing up holidays, cartoons, and commercials, and risk being discovered by Agent Umber.

With a mysterious new principal and fifth-grade graduation fast approaching, Michael K. and his friends need to find the missing Brainwave before the chief of the Anti-Alien Agency uses it to destroy a planet.