The R of the title stands for the young protagonist, Rune, fearlessly played by Pilou Asbæk. Imprisoned for violent assault, he's a cocky, good-looking young man placed in the hardcore ward, where his survival depends on quickly learning the prison's parallel world of rules, honor, and obligations. R also stands for Rachid, a young Muslim prisoner who becomes Rune's friend and accomplice, defying the rigid racial stratifications among the inmates.
Company commander Claus Michael Pedersen and his men are stationed in Helmand, Afghanistan. Meanwhile back in Denmark, with a husband at war and three children missing their father, everyday life is a struggle for Claus' wife Maria. During a routine mission, the soldiers are caught in heavy Taliban crossfire. In order to save his men, Claus makes a decision that ultimately sees him return to Denmark accused of a war crime.
Zaid is a successful heart surgeon with an expensive apartment and pregnant girlfriend. One night he gets a visit from his brother Yasin, who is desperate for money, but he refuses. Soon after, Yasin is found beaten to death and Zaid is overcome with guilt. As guilt gives way to anger, Zaid becomes a masked avenger and takes on Copenhagen's criminal underworld in his quest for justice.
