Sammi takes charge as a prison guard in a big, old prison called Huset, where the strong inmates dominate the weak. The prison guards receive a shocking message.

The clean-up campaign begins as two consultants from the Correctional Service monitor how the prison is run; prison guard Miriam attempts to repay her son's debt.

The information from Sammi's secret source leads to more successful raids, which impresses the consultants but puts the strong inmates under pressure and makes them desperate as their business is ruined.

The inmates suspect there is a snitch among them; Gert wonders how new drugs keep coming in; a big fight with handmade weapons takes place.

News spreads that there is a dirty cop in the prison, so new precautions are taken to smuggle in; the four guards face challenges when they receive a devastating message about the inmate they put in an unauthorised leg lock.

The officers tensely wait for the response to the death of the inmate as the two rival gangs begin to talk to each other; a huge prisoner riot breaks out.