Every year at the end of July, the Jan Baalsrud March takes place. It is 200 kilometers long and crosses the islands of Rebbenesøya and Ringvassøya, the Lyngen peninsula and the mainland east of Lyngenfjorden. The march takes eight days and you can do either all of the march or just part of it.
Preparing for the role of Jan Baalsrud, Thomas Gullestad practiced looking cold in front of a mirror. After filming, Thomas admitted during a radio interview that it was not necessary. Looking cold came very naturally while filming as it was, in fact, very cold.
During filming on location at Lyngseidet, two Italian skiing tourists was caught in a big avalanche in the mountain nearby the set. It was in the very same mountains and during the very same time of year that Jan Baalsrud made his long escape from the German occupiers. At the time of his escape, he was well aware of the dangers of avalanches and the risk he took in the same areas.
The failed mission at the start of the movie was Operation Martin. Aimed at destroying a German air control tower at Bardufoss. It was also tasked with organizing secret military resistance groups in Tromsø in German-occupied Norway in 1943.
Operation Martin was compromised when the Norwegian operatives seeking a trusted local resistance contact, accidentally made contact with an unaligned civilian shopkeeper with the same name as their contact. The civilian reported them to the Germans.