In the tumultuous backdrop of late 1944, a significant shift occurs as Finland forges a treaty with the Soviet Union, thereby determining that an end to hostilities will arise only if the remnants of their former German allies are expelled from Finnish territory. This tumultuous period, known as the Lapland War, sees the German forces retaliating against the Finns.
Living a solitary existence in the harsh wilderness of Lapland is Aatami Korpi, portrayed by Jorma Tommila, a retired commando and prospector who shares his days with just his horse and loyal dog. While he finds solace in mining and searching for gold, distant battles capture his attention only momentarily. Aatami stumbles upon a significant gold cache, and after gathering a generous fortune in nuggets, he sets off towards the nearest town with his canine companion in tow.
However, fate has other plans as he crosses paths with a Wehrmacht platoon, commanded by the merciless SS Obersturmführer Bruno Helldorf, played by Aksel Hennie, along with his subordinate Wolf, enacted by Jack Doolan. This German platoon, in their retreat, is wreaking havoc, destroying settlements, and taking Finnish women captive. Though Helldorf shows little interest in Aatami’s activities, his fortune changes swiftly when a second group of soldiers, upon discovering Aatami’s gold, aims to execute him. In an impressive display of survival instinct, Aatami dispatches them promptly.
The sound of gunfire piques Bruno's curiosity, leading him to the scene of chaos where he finds a gold nugget left behind by one of the dying soldiers. As he pieces together Aatami's identity, he learns that Aatami was once a heroic Finnish commando, who had lost everything during the Winter War. This transformation leaves Aatami as a feared figure known as Koschei, the "Immortal," who has claimed the lives of hundreds.
Despite receiving warnings, Bruno pushes forward, intent on capturing Aatami. The ever-resourceful Aatami, now wounded and weary, cunningly uses his surroundings to evade capture. Hiding under a German vehicle, he sabotages its fuel tank, creating a diversion that allows him to escape the watchful eyes of his pursuers.
Tragically, it’s not long before Aatami’s horse and the gold he seeks become victims of a minefield. The stakes escalate when Bruno orders two captive women to lead the way through the field, and Aino, played by Mimosa Willamo, courageously steps forward to guide them. As events unfold, Bruno uncovers Aatami's past, igniting a personal vendetta against the legendary warrior.
In a desperate series of encounters, Aatami faces peril while trying to save his dog, thwarting an explosive attempt by Bruno. Captured and strung up by the petrol station's sign, Aatami's fate seems grim, but in a twist of chance involving German pilots searching for fuel, he narrowly escapes with his life. Meanwhile, Bruno plots to flee the impending doom of a defeated Germany using Aatami’s gold.
As tensions rise and the stakes become life-or-death, Aatami embarks on a haunting journey of vengeance against Bruno and his platoon. In what becomes a fierce showdown, Aatami not only battles his enemies but also grapples with the emotional weight of his past as he valiantly seeks justice for his lost family and the destruction left in the wake of war.
In a gripping climax, Aatami confronts his nemesis in a battle of strength and cunning aboard a crashing plane, leading to a stunning resolution that brings him back to the ravaged landscape of Helsinki, gold nuggets in hand. As he enters a bank, his appearance starkly contrasts the well-dressed patrons, and for the first time, he expresses his desire to exchange his hard-won gold for something lighter to carry, underlining the burden of his journey through conflict and loss.
