Don't Judge a Girl by Her Cover

The novel follows Cammie Morgan, a sixteen-year-old student at the Gallagher Academy for Exceptional Young Women, a school that appears to be an elite finishing school but secretly trains young women as spies. The story opens in Boston, where Cammie attends the national political convention at which her roommate Macey McHenry's father, Senator James McHenry, will accept the vice presidential nomination. Macey is furious with her mother, who is pressuring her to appear publicly with Preston Winters, the presidential candidate's son, for political gain.

After a rehearsal, Cammie, Macey, and Preston take a service elevator that opens onto a utility floor instead of their expected destination. When they step onto the hotel roof, three masked attackers strike with precision and coordination. Cammie fights them using her spy training and gets Preston to safety on a window-washing platform. The attackers ignore Preston; the woman among them points at Macey and orders, "Get her." During the struggle, Cammie notices a gold ring with a distinctive emblem on one attacker's hand. Macey's arm is broken, and Cammie pushes her through a vent. They escape down a laundry chute, where Cammie hits her head and blacks out.

She wakes at a lake house owned by her Covert Operations teacher, Joe Solomon. Her mother, Rachel Morgan, who is the Gallagher Academy's headmistress, explains the attack was a kidnapping attempt. Cammie is coached on a cover story for the FBI: She was just a girl who got lucky. At the pier, Macey stands withdrawn, whispering that the water feels safe, before her parents take her back to the campaign trail.

When the fall semester begins, Macey's return triggers a Code Red, the protocol for concealing the school's true nature from outsiders. Rachel introduces Agent Abigail Cameron, Cammie's aunt and a Gallagher alumna, as Macey's full-time Secret Service protector. Cammie is stunned; she has not seen Aunt Abby since before her father's death years ago. Abby is glamorous and confident but clashes with Macey over security restrictions.

In their first class on Sublevel Two, a newly accessible underground labyrinth of classified archives, Solomon shows the junior covert operations class uncensored footage of the Boston attack. Watching the footage, Cammie notices something she missed in the moment: the attackers targeted Macey alone, ignoring Preston entirely. She keeps this realization secret. She also receives a cryptic postcard from Zach, a boy from the Blackthorne Institute, a rival school that trains boys as spies, whom she kissed the previous semester. The card reads: "Be careful."

When Solomon takes the class to observe Secret Service protocols at a campaign rally, Cammie spots a figure near a restricted area and discovers Zach. He is evasive about his presence and vanishes before being seen. Back at school, Cammie and her roommates investigate the attack. Bex Baxter and Liz Sutton, Cammie's closest friends and classmates, join Macey in researching McHenry family enemies, but the suspect list yields no clear answers. Cammie remains fixated on the ring's emblem; Liz runs it through every intelligence database and finds nothing. The girls break into Abby's room and discover a satellite photograph of the ring, confirming the intelligence community is also tracking it.

When Macey travels to a fundraiser in Philadelphia, Cammie, Bex, and Liz secretly follow in a prototype minivan Liz built with the school's research department. Disguised with wigs and prosthetics, they infiltrate the event. Cammie spots a white-haired man and follows him into a train tunnel, where she sees him meeting with Solomon. She realizes the man is Zach in disguise, confirming he was also present at the Boston attack. She boards the campaign train to confront him, but Abby approaches, and Zach escapes by parachuting off the moving train. Abby confronts Cammie furiously, and Cammie erupts with suppressed grief, demanding to know where Abby was when her father died. Abby offers no explanation and warns Cammie to stay away from Zach. When Macey notes they know Zach from Blackthorne, Abby replies, "Do you?"

Rachel grounds Cammie and decides Macey will remain at school. During a covert operations lecture, Solomon lists six reasons anyone does anything: love, faith, greed, boredom, fear, and revenge. The lesson triggers a breakthrough. In the library, Cammie matches the ring's emblem to the symbol on the hilt of a sword belonging to Gillian Gallagher, the school's founder, who killed Ioseph Cavan in 1864. Cavan founded the Circle of Cavan, a secret organization that has opposed the Gallagher Academy ever since. The girls conclude the Circle is targeting Macey because she is Gilly's last living descendant, a fact revealed to Cammie and her roommates the previous year but unknown to Macey.

Cammie debates telling Macey but decides to wait, deferring to the adults' silence and Liz's argument that Macey would already know if she needed to. She takes Macey out through a secret passage for a night at a local football game, where Macey savors the anonymity of being unrecognized. Zach appears, and during their exchange, Macey overhears them discussing the Circle. She learns she is Gilly's descendant and is devastated, believing she was admitted to the school only because of her bloodline. She runs away, creating a decoy who flies to Switzerland while she hides elsewhere. After days of searching, Cammie realizes Macey would go somewhere she felt safe, drives to Solomon's lake house, and finds Macey waiting. Macey acknowledges her bloodline may explain her admission but adds, "That's not why they keep me."

On Election Night, the girls bring Macey to the Winters-McHenry watch party in Washington, D.C. Zach appears and leads Cammie outside. The power goes out across three city blocks, a van crashes through barricades, and masked figures bypass Macey entirely, lunging for Cammie. The Circle's true target was never Macey but Cammie. She fights back but is overpowered as a drugged rag covers her face. In the chaos, a gunshot rings out. From her disoriented perspective, Cammie sees someone lunge in front of Macey before spotting Aunt Abby bleeding on the ground. Solomon screams for agents to protect Cammie. One attacker recognizes Zach and flees.

Cammie wakes in her mother's office. Abby survives surgery. Rachel and Solomon confirm they suspected Cammie was the true target after Zach shared intelligence with Solomon in Philadelphia. Solomon says Zach "has sources" but will not elaborate. Rachel promises to find out why the Circle wants Cammie. Weeks later, Abby departs on a new CIA assignment after kissing Solomon in front of everyone. Cammie asks her not to disappear again. In the pocket of Zach's jacket, which Abby returns to her, Cammie finds a note on dissolving paper: "Have fun in London." She resolves to wait for spring, when answers may come.

In an epilogue told from a third-person perspective, Abby reveals to Solomon that the man captured in the D.C. attack has begun talking. Solomon departs alone, asking Abby to take care of Rachel. After he leaves, Abby receives a call from a British intelligence agent who says they need to talk about Joe Solomon, implying Solomon himself may be connected to the danger.