In the fourth season, a woman is found brutally murdered on a small artificial Danish island close to the Øresund Bridge. The woman is Margrethe Thormod, Thormod, Director General of the Migration Agency in Copenhagen, who was recently embroiled in a deportation scandal. Danish detective Henrik begins to investigate the murder without the involvement of Saga, due to the fact that she has now been imprisoned for the murder of her mother. Henrik is missing his colleague and wants to visit her as often as possible so she can help with the case. However, her predicament renders her unable to help. Henrik’s search for his missing daughters is also frustrated by Saga’s imprisonment and he gets close to giving up.
第二季中，侦探杜尔西·柯林斯（凯特·波克斯 Kate Box 饰）和埃迪·雷德克利夫（玛德琳·萨米 Madeleine Sami 饰）将前往澳大利亚的Top End地区。她们起初在达尔文调查雷德克利夫前任警务伙伴布什的死亡案件，然而在一个偏远小镇发现了两名Top End知名人士的尸体，这开启了一场“更紧张、更棘手”的新调查。
