The opening text states that the term “Sisu” is Finnish and has no direct translation but is essentially a force of unstoppable determination that comes out when most necessary. A narrator then starts by stating that it is three years into World War II (1944). Finland has agreed to an armistice with the Soviet Union to drive German troops out of their country. The Nazis have begun to employ scorched earth tactics, destroying towns, roads, and bridges and capturing people.
Chapter One: The Gold
In Lapland, a prospector named Aatami Korpi (Jorma Tamilla) is with his little dog in an area mining for gold. He finds a little gold nugget and camps in the area over a few nights while enemy planes fly overhead. Eventually, Aatami manages to find a plentiful gold deposit in the dirt, causing him to cheer. He gathers his gold and starts to make his way to the nearest bank.
A Nazi platoon led by Bruno Helldorf (Aksel Hennie) makes its way through the land, taking with them a group of women as their prisoners. A small group of Nazis encounters Aatami and the dog while he rides on his horse. They stop him and demand to inspect his belongings. Aatami sends the dog to run away and hide while the Nazis start shooting at him. The lead Nazi finds Aatami’s gold and starts to taunt him, saying he and the others will take it. Aatami responds by grabbing a knife and sticking it in the Nazi’s head. He then proceeds to stab and shoot the remaining Nazis, including using one as a human shield. Aatami proceeds on the horse.
Helldorf and his goons find their comrades’ corpses and a gold rock that was left behind. They follow Aatami’s trail and begin to shoot at him. The horse manages to outrun the gunfire, but they run over a mine, and the horse is blown to bits. Aatami mourns his horse before having to hide.
Chapter Three: The Minefield
Helldorf and the other Nazis find Aatami and corner him. He spots a nearby mine and throws a rock at it, creating an explosion that helps hide him. The Nazis starts to open fire in his direction. Helldorf sends a young Nazi out to see if Aatami is still alive. Aatami throws a minefield at the Nazi’s head, blowing him up. Helldorf sends two more men out to run, forcing them to run into mines and get blown up as well. The Nazis continue their gunfire, which Aatami blocks with a shield. One of the female prisoners, Aino (Mimosa Willamo), volunteers to go up ahead along with a second woman.
Chapter Four: The Legend
As the Nazis proceed forward, Helldorf talks to one of his mates that found Aatami’s dog tags, and who knows about Aatami and his history of serving in the Winter War. He lost his family to the Russians, and he has since earned a reputation for being a ruthless killing machine that some have taken to calling “Koschei”/”The Immortal.” Helldorf intends to get the gold because he knows that the Nazi party will soon lose its power, and the gold will be their way to retire in peace.
Aatami runs and hides until the Nazi convoy drives past, and he rolls under one of their vans. He cuts one of the gas lines to mask his scent from the Nazis’ attack dogs. Helldorf and the others stop when they smell the gas. They catch Aatami and try to kill him, but he sparks a match that ignites the gas he is covered in, setting himself on fire until he runs into a nearby lake. The Nazis shoot at him, but Helldorf waits for him to come up for air. He then sends three Nazis on a boat to dive in after him. Two men dive in, and Aatami slits their throats and takes their remaining air. The third man starts to ride the boat away, but Helldorf has him shot for trying to desert them. Aatami gets on the boat and escapes, but Helldorf gets the dog.
Chapter Five: Scorched Earth
Aatami comes upon a town devastated by the Nazis’ tactics. He finds an abandoned gas station where Helldorf sends the dog to run to his master, with a stick of dynamite attached to him. Aatami removes the dynamite but gets thrown by the explosion. Helldorf, plus his two goons Wolf (Jack Doonan) and Schutze (Onni Tommilla), show up and tie Aatami up by the neck to hang him before stealing the rest of his gold. Aatami manages to hook one of his wounds from the explosion onto a nearby pole to save himself from the noose.
The following morning, a pair of German pilots come by to get fuel. They find Aatami and attempt to antagonize him, but Aatami stabs one to death and knocks the other unconscious. When he comes to, Aatami makes him fly him closer to the platoon before hanging him and leaving him for the Nazis to find.
Chapter Six: Kill ‘Em All
Aatami catches up to the convoy as they head toward Norway to make their escape with the gold. He gets ahold of some guns and gives them to Aino and the other women. Aatami pulls one Nazi out onto the street, where he gets run over by a tank. The women then arm themselves and pump the Nazis full of lead. Aatami commandeers a tank and pulls Wolf out, leaving him to be taken by the women.
Helldorf and Schutze meet with their pilot to get them out, but Helldorf shoots Schutze in the head and leaves with the pilot himself. Aatami catches up to them and shoots at them with the tank, hitting the pilot. Aatami then uses his pickaxe to hook himself onto the plane as it takes off. He breaks his way inside, with Helldorf confronting him. He starts to beat Aatami ferociously, even using a static line to slice into his face. However, Aatami waits for the right moment to grab the line and hook it onto a nearby bomb, dropping it from the plane with Helldorf attached to it, sending him plummeting to his explosive death. Aatami then goes into the cockpit where the pilot has died, and he braces for impact as the plane crashes.
Final Chapter
Aino and the other imprisoned women deliver Wolf to the Finnish army. Meanwhile, Aatami pulls himself out of a swamp and finds a motorcycle, also reuniting with the dog in the process.
Aatami rides to Helsinki, where he arrives at a bank. Everyone stares at the filth-covered prospector entering with his pickaxe. He takes the recovered gold to a teller and dumps it all on the counter. Aatami (who has been silent the entire movie) finally speaks, requesting large bills because “they won’t be such a bitch to carry.”
