Arnaldur, a 16-year-old boy living a normal teenager's life in Reykjavik. One day, coming home from school, he finds his brother in the bathtub, dead. Despite clear signs of a suicide, Arnaldur is convinced that his brother's teacher is somehow responsible so he decides to take matters into his own hands and avenge his brother.
Styr Júlíusson
Arnaldur
Davíð Guðbrandsson
Arnaldur's father

Hilmir Snær Guðnason
Drunk man

Damon Younger
Magga's father

Þorsteinn Bachmann
Police Sergeant
Ísak Hinriksson
Júlli

Hjalti Rúnar Jónsson
Gulli

Arndís Hrönn Egilsdóttir
Júlli's mother
Kristján Hafþórsson
Höddi
Alexía Björg Jóhannesdóttir
Arnaldur's mother

Thor Tulinius
Police officer #1
Aron Brink Sigurjónsson
Bjössi Tango

Rakel Björk Björnsdóttir
Magga
Hjálmar Óli Hjálmarsson
Þór Jóhannesson
Police detective #2