In the opening of Episode 2 of "Flunked," Eddy hurls his bag over the gates and dashes towards the school, unheeding the security guard's hidden warning. Inside the school, every corner is eerily quiet, and Eddy discovers the teachers and students huddled under their desks. A masked figure carrying a baseball bat enters the scene, prompting Eddy to seek refuge in a washroom. There, he encounters a girl hiding and uses her as bait. When the masked figure approaches, Eddy launches an attack, only to realize it was all part of a safety drill in anticipation of a terrorist invasion. The masked figure is revealed to be Viviane. The teachers escort Viviane to the teachers' lounge for medication, while Eddy is summoned to the principal's office.
Tiphaine is furious with Eddy for not checking his notifications and asks him to straighten up his act. In the lounge, the teachers express their anger towards Eddy for having to repeat the safety drill. Viviane is limping and Gilbert urges her to rest, but she insists on attending the retirement party for art teacher Corinne. Meanwhile, Pablo seeks Viviane's help with filling out the Parcoursup, a platform where students enter their post-graduation plans.
Eddy deduces that Sagirov's child must not have filled in their details as Sagirov wanted to exfiltrate his kid. Lucie informs him that three nearby cell towers were activated when Sagirov messaged his ex. After some analysis, they identify 13 students as potential targets. Since Lucie cannot access it from outside, Eddy decides to hack it. To do so, he befriends Brigitte, the janitor who has keys to the principal's office. He cleans the toilet, engages in small talk, and cleverly steals the keys.
Eddy sneaks into Tiphaine's cabin, risking being caught by security. Once safe, he logs into the computer but risks getting caught again this time by Tiphaine. He hides under her desk as she completes her task while listening to a song that holds a special connection between her and Eddy.
The following day, Eddy discovers the entire class in a state of shock and grief. It emerges that his hurried attempt to switch off the computer had inadvertently deleted crucial data and validated the rest on the Parcoursup platform, forcing everyone to manually re-enter the information. With finals looming in less than three weeks, this added stress becomes unbearable.
The parents are enraged, and Tiphaine, though suspicious of Eddy, tries to pacify them. He insists on his innocence, but the situation remains tense. In the classroom, students are also worried, but Eddy tries to reassure them, even engaging in a cordial conversation with Kylian, whom he had previously punched.
Tiphaine speaks to everyone who has access to the principal's office. The janitor reveals that she has lost her keys. Eddy enlists her help and slips the keys into her purse along with its contents. Tiphaine enlists the police to resolve the matter.
Eddy reaches out to Lucie to handle the matter with the Lille police, but she asserts that only she and the judge are aware of his undercover role. They argue once again about their personal matters.
Eddy, realizing that his fingerprints will be found without gloves, attempts to clean them before the police arrive. When that fails, he convinces Gilbert to take the blame by painting him a dream of retirement and fishing. Gilbert quickly agrees and confesses, resulting in a six-month suspension that he plans to combine with his remaining pay to start his retirement.
As the school prepares for a trip to Normandy, Lucie continues working on the case. At their home, Tiphaine arrives to apologize to Eddy for having doubted him. Eddy begins to suspect that Tiphaine might have feelings for him, as Lucie narrows down the suspect list to five, including Tiphaine as a potential mother of Sagirov's child.
