The time-honoured system of depriving prison inmates of their personality by replacing their names with a number is one of the first things incoming residents face at the remote Bastøy nick.
Except these aren't hardened criminals or wordly lags...this is Norway in 1915 and these are mere boys - some whose ages aren't even in double figures - who have been sent to the isolated jail for charges as minor as dipping into the the church collection tin.
The prison is ruled over by Håkon (Skarsgård), a brutal disciplinarian who cites the Almighty as the ultimate authority and delegates the job of running the grim stone slammer to housefathers, including Joner's Braaten, a harsh overseer whose vindictive manner cloaks a propensity for kiddie-fiddling.
Into this cold world steps Erling (Helstad), a former naval rating who may or may not have killed someone, and whose reputation - and anti-establishment demeanour - immediately command respect. Among the inmates, anyway.
He's also attracts the ire - and possibly fear - of the repulsive Braaten, who is determine to break him.
This plays out a bit like Scum-in-the-snow but is thoroughly compelling thanks to a brooding performance from Helstad as the strongly moral rebel whose mental strength elevates him above the vindictive regime (and it's facile attempt to strip him of his personality by labelling him C19).
Based on a true story when the Norwegian army were called in to quell a mutiny at the prison, this may be a familiar tale - rough-around-the edges dissenter against a barbaric system - but it's well told and the icy wastes of the island provide a chilling backdrop to the cruelty dealt out to the boys.