When her history teacher begins receiving death threats and her own name is near the top of the suspect list, eighth-grader Sammy is determined to find the real perpetrator, but she is distracted by her mother's relationship problems, her almost-boyfriend inexplicably avoiding her, and her duties as a reluctant bridesmaid.

Someone is spray-painting graffiti all over Cedar Valley and it is up to fifth-grader Nolan Byrd, also known as Shredderman, to expose the vandal.

Seventh-grader Dave Sanchez and his talking gecko sidekick Sticky decide they must rescue an odious science teacher who has been kidnapped by the even more villanous Damien Black, who is masquerading as a substitute teacher in order to steal Dave's magic Aztec armband.