When a bank is robbed, not by a holdup but electronically through bogus wire transfers, the boys find a clue pointing to an exclusive private boarding prep school named Chartwell Academy, the boys decide to infiltrate as students. Frank makes the cut academically to get in, but Joe does not. He takes a job as a custodian.
While attending the school, Frank meets a cast of characters - the punk rock fan Arnie, the preppy Brad, the Dumb Jock Dwight, who is also the son of the manager of the bank that was robbed, scholarship student Sarah and her jealous ex Stu, technical genius Ty and charismatic chemistry teacher Jim Castigan.
But just when it looks like Frank is getting close to finding the thieves, someone alters his academic records so he is in danger of flunking out. This forces the boys to resort to desperate measures.
Tropes found here are:
- Boarding School: Chartwell is the New England variety, intended as a private prep school for kids who want to get accepted into elite universities.
- Brainwashed and Crazy / Hate Plague: Castigan sprays Dwight with a fear- and violence-inducing “pheromone” that causes him to go berserk and attack anyone in the vicinity. In the climax, he does the same to Joe.
- Buried Alive: Castigan tries to do this to Frank in the finale. Even worse, he tries to force a Brainwashed and Crazy Joe to be the one to actually bury him, but Joe, despite being insane, manages to avoid completely covering Frank.
- Crazy Jealous Guy: Stu is extremely possessive of Sarah and picks a fight with Frank for just talking to her.
- Creepy Cemetery: The masked gunman chases the boys through one in the climax, and corners them when Frank falls into an open grave and Joe, while avoiding doing so as well, sprains his ankle.
- Dumb Jock: Dwight Trilby is one. However, despite how he initially comes across, he's a subversion of a Jerk Jock, and once the Hardys reveal their identity and true intent to him, he readily agrees to assist them.
- Eat the Rich: Why Castigan and the Scholarship Students Stu, Ty, Lloyd, and Sarah robbed the bank.
- Evil Teacher: The Big Bad of the book turns out to be Jim Castigan, the chemistry teacher at Chartwell.
- Girl of the Week: Sarah Waterbury is the most prominent girl in the book, and has a mutual attraction with Frank. Similar to this trope in the previous book, though, she turns out to be a Love-Interest Traitor who is in on the plot.
- Harmless Electrocution: How Joe is ultimately un-brainwashed from the rage pheromones when Frank is unable to calm him down himself. In his rage-induced frenzy, Joe accidentally electrocutes himself with the car radio, which merely knocks him unconscious for a few minutes. When he wakes up, he's mentally back to normal, and physically none the worse for wear.
- Hoist by His Own Petard: Castigan decides to murder the Hardys by spraying Joe with the same rage-inducing pheromones he used on Dwight, use his subsequent violent mental state to get him to bury Frank alive, and then finish Joe off himself. However, the pheromones drive Joe crazy so quickly that he stops shoveling dirt before burying Frank all the way, and when Castigan finally decides to Just Shoot Him, a rage-crazed Joe throws the shovel at him and knocks him out.
- Let's You and Him Fight: The reason that Castigan pulls the above Brainwashed and Crazy moments on Dwight and Joe at different times:
- It causes Dwight to turn against the Hardys, attacking and nearly killing them, which gives Castigan an opportunity to flee. Luckily, they manage to fend off his attacks long enough to knock him out.
- At gunpoint, Castigan forces Joe to start burying Frank alive in the open grave, knowing that, even though Joe will try to be as slow as possible at first, once the pheromones kick in, he won't be conscious of what he's doing and will fully bury Frank for real. It almost works, but Joe doesn't cover Frank's head before totally losing his marbles.
- Love-Interest Traitor: Frank develops a crush on Sarah, but discovers in the end that she's one of the bad guys. The "traitor" part is really hammered home when he calls her for help in escaping the masked gunman who's pursuing the Hardys...only for the gunman to show up instead of her, and they realize that she betrayed them.
- Romantic False Lead: Despite having a girlfriend in Callie, Frank finds himself falling for Sarah...until he finds out that she is one of the thieves.
- Why Don't You Just Shoot Him?: Castigan outright lampshades that he could just shoot the Hardys while they're helpless and can't flee, but decides to spray Joe with Hate Plague pheromones and basically make him do the work of burying Frank alive before finishing Joe off himself. This causes the above Hoist by His Own Petard moment.
- Worf Had the Flu: When the masked gunman (Castigan) chases the Hardys, they try to run from him in the Creepy Cemetery, but Frank falls into an open grave, while Joe avoids this at the cost of spraining his ankle. This leaves both of them unable to either flee or fight back once Castigan corners them (at least until he causes his own undoing by spraying Joe with the pheromones, essentially negating the damage to his ankle).
