H3L is the class every teenager wants to be in, but is every teacher's nightmare. The students, underestimated and pigeonholed by everyone, have to deal with drugs, discrimination, jealousy, sex, and setting boundaries. For these students, ultimately, it is mostly about love and friendship.

After Ashraf's death and Samira's conviction, Tonnano finds himself surrounded by enemies in Amsterdam. With the birth of his son, Tonnano decides to change course. He wants to build an honest life where Amani, the mother of his baby, and her family live: the Achterhoek region. However, his arrival causes unrest within the notorious Eysinck drug family, who have ruled the region for years. When Badr, Amani's uncle, turns out to be in debt to this family, jeopardizing Tonnano's new life, he becomes enraged. Tonnano takes on the notorious family. Who will become the new boss of the Achterhoek region?

The series follows criminology professor Mia van der Linden who chooses a small group of students to solve cold cases. But during their work they come across a case that they are suddenly no longer allowed to investigate by higher authorities. The group of students must use the law cunningly to find justice.