During the Nazi occupation of Denmark in the Second World War, the Danish resistance movement grew through sabotage and underground activities against the German occupiers. Among those connected to the resistance was Grethe Bartram, a young Danish woman who became one of the most notorious informers of the occupation.

Working for the Gestapo under the codename “Thora,” Bartram betrayed resistance members, friends, and even members of her own family. Her information led to arrests, interrogations, and deportations to Nazi concentration camps.

The story follows the German occupation of Denmark, the rise of the resistance movement, and the actions of one of Denmark’s most controversial wartime collaborators.