When Cammie "The Chameleon" Morgan visits her roommate Macey in Boston, she thinks she's in for an exciting end to her summer break. After all, she's there to watch Macey's father accept the nomination for vice president of the United States. But when you go to the world's best school (for spies), "exciting" and "deadly" are never far apart. Cammie and Macey soon find themselves trapped in a kidnappers' plot, with only their espionage skills to save them.

As her junior year begins, Cammie can't shake the memory of what happened in Boston, and even the Gallagher Academy for Exceptional Young Women doesn't feel like the safe haven it once did. Shocking secrets and old flames seem to lurk around every one of the mansion's corners as Cammie and her friends struggle to answer the questions, Who is after Macey? And how can the Gallagher Girls keep her safe?

Soon Cammie is joining Bex and Liz as Macey's private security team on the campaign trail. The girls must use their spy training at every turn as the stakes are raised, and Cammie gets closer and closer to the shocking truth.