The series is named after the lead character, a half-Icelandic half-Danish police officer named Hallgrim Ørn Hallgrimsson, nicknamed "Ørnen" (the eagle). A new international criminal investigative unit is being formed under Thea Nellemann, and Hallgrimsson is persuaded to take the job as the lead investigator for the unit. He puts together a small investigation team that are experts in their respective fields. Their cases cross the borders between Norway, Sweden, Denmark, Russia and various other countries; and involve biker gangs, former Russian KGB, possible terrorist threats and international fraud. Throughout the series Hallgrimsson deals with recurring flashbacks and possibly post-traumatic stress from a childhood incident.