
When small-time crook Eddy gets caught fleeing a club raid, he's offered a choice: serve jail time or go undercover as a math teacher in a high school.

A tense safety drill and Eddy's late-night meddling send the school into chaos, putting him at the center of suspicion — and closer to Tiphaine.

On a class trip to Normandy, Eddy clumsily attempts to collect DNA samples for Lucie, and a botched attempt to impress Tiphaine sparks controversy.

While a blockade at the school brings mass media attention, Eddy attempts to uncover a mole among the teachers, leading to a politically charged protest.

Professor Fish goes viral across France as Lucie attempts to strike a deal with Sagirov's contact and Eddy makes a stand on local television.

Someone from the past sheds new light and fresh doubts on the case, while Eddy sets up a parent‑teacher meeting so Lucie can hunt for clues.