It is the start of the semester at Tuna Kvarn boarding school and at the municipal school Holmered. Hugo, Caroline and Philip are preparing for this year's zebra room election. Nasim carries a secret.

A body has been found in Svartån and several people from yesterday have not been seen. An outrageous clip is spread through an unknown person. Carl presents his new investment project in a different way.

Sara is on enemy soil, and Isaac is being vindicated. The annual relay between the schools will take place, but will not be as Sara had hoped. Philip and Hugo are planning for the upcoming long weekend.

Preparations are underway for two parties - Philip's "home party" and Carl's annual reunion. The work of the police continues while the parties for some people are closer together, and some further away.

Sara gets an unexpected visit from her past. Caroline's pressuring Hugo. Meanwhile, William makes a huge decision. Philip's romantic plans go awry, while Isaac gets into the heat.

Autumn has come, some time has passed. Grace and Louise will fix up for the play. Hugo's trying to correct his mistake. Carl is disappointed in the Zebra room, while Kenneth has nothing left to lose.

Isaac finds himself in his worst nightmare, and the new clip that has spread stirs emotions. Carl gets a call. Sara puts the connections together and gets closer and closer to the core.