The antagonist in cross your heart and hope to spy?

The antagonist in "Cross My Heart and Hope to Spy" is a character named Josh Abrams. He is a fellow student at the Gallagher Academy for Exceptional Young Women who is revealed to be a double agent working for the Circle, a secret organization. Josh's betrayal poses a significant threat to the protagonist, Cammie Morgan, and her friends as they navigate the world of espionage and try to uncover the truth behind his actions.