“Was it worth it? –  There’s no way to answer that – what is freedom worth?” So says veteran Gunnar Sønsteby in response to a student question after delivering his account of life as a Norwegian resistance fighter during the Second World War. It’s the central question that director  John Andreas Andersen asks in Number 24 and one that he doesn’t provide easy answers for.

Based on the real-life story of Sønsteby, Andersen frames the narrative through the elderly Sønsteby sharing his remarkable story to a group of students. Despite it being a story he has told on countless occasions prior, it still remains a raw emotional feat for the former resistance fighter, a story that he has compartmentalised in his mind to protect himself, and now to protect others, of the true horrors he faced during that turbulent time.

He describes his memories as being filed away in five drawers in his mind. The top three drawers he visits frequently, the fourth containing more painful memories just occasionally and the fifth drawer has remained firmly shut since the end of the war in 1945.

While it may be shut to him, director Andersen gives us a peek inside that closed drawer, looking at some of the impossible decisions Sønsteby, and his fellow resistance movement members, had to take during those dark times.

Jumping from the modern back to the events of the War, we first meet Sønsteby prewar, skiing with his best friend in the mountains of Norway, learning of the rise of the Nazis in Germany. There’s a difference of opinion between the friends on the threat of the Nazis, one that will send the pair on dramatically different tracks. These differences will haunt Sønsteby until his death.

As war eventually breaks out and Oslo is taken by just 800 German soldiers, the fledgling Norwegian resistance soon recruits Sønsteby, who as agent ‘Number 24’, soon develops a knack of vanishing into the background through several false identities. It’s a risky life, Norwegian conspirators and the occupying Germans making it hard to trust anyone.

Andersen’s direction never shies away from the horrors of war, nor the summary justice meted out by either side. It is though far from an all-action military romp, instead Andersen focuses on the human impact,  the psychological impact of having to always be one step ahead to survive. The set-piece action moments are there – the bombing of key infrastructure and the execution of collaborators all ramp up the tension – but here they are shown as more context to the more human impact.

It is those executions of fellow Norwegians, identified by Alli forces as collaborators, that perhaps cause the older Sønsteby most destress and provide most of the content of his locked ‘fifth drawer’. Attacking faceless enemies is one thing, but when tasked with eliminating your own countrymen it is a very different matter.

Andersen directs Number 24 in a documentary style, flipping from modern Norway to war-time Norway with ease. The sabotage attacks on key infrastructure provide enough spark to remind us of the dangers of war but at its heart this is two-hander through the eyes of the elder and younger Sønsteby. Sjur Vatne Brean as the younger captures the resistance hero remarkably. Focused and driven yet also blessed with the perfect poker face that lets himself blend into the background and become the invisible man. As the elder, Erik Hivju is equally captivating, proud and resolute in his achievements but still inwardly tortured by the decisions war forced upon him.

As befitting a documentary approach, Andersen doesn’t judge, his challenge comes though the voices of the students listening to Sønsteby’s testimony. A generation removed from war they have a different outlook on life and their questions over the use of violence as opposed to diplomacy don’t receive a resolution here – nor should they.

Where Number 24 succeeds is showcasing perhaps still a lesser-known area of the Second World War. While the French Resistance is now well-known, its Norwegian counterpart is perhaps less featured outside of the country. Regardless of nationality, though, what Number 24 manages to portray with both skill and sensitivity is the true cost of any conflict on the human soul, even decades after hostilities have ceased.

Number 24 is now streaming on Netflix