As the snow-covered peaks of Norway create a breathtaking backdrop, a tense escape scene reveals a horrifying fate for Sara, whose frantic efforts to evade danger ultimately lead her to the merciless grips of reanimated Nazi soldiers, their World War II uniforms now tarnished by fresh blood. Meanwhile, a group of seven students has arrived for an Easter vacation at a secluded cabin near Øksfjord, the property of Vegard, Sara's boyfriend. As they settle in for a night filled with celebration, a strange hiker appears, sharing chilling tales about the area's dark history, where war’s horrors still reverberate.
During World War II, a ruthless Einsatzgruppe, commanded by the infamous Standartenführer Herzog, laid waste to the region, committing unspeakable atrocities against the locals. As Germany faced impending defeat, the Nazis ravaged the town, only to be met with fierce resistance from the resentful inhabitants, who mounted a bloody revolt that nearly annihilated their oppressors. The surviving soldiers, including Herzog, retreated into the mountains, presumed dead, but the grim legacy of their past is far from concluded.
That night, Vegard's sleep is broken by what he believes is Sara stirring beneath the floorboards, but his calls go unanswered, leaving him feeling disturbed and perplexed. His tranquility shatters upon discovering Sara drenched in blood outside, though it is merely a nightmare, and he awakens alone. Meanwhile, the hiker camps in the mountains, enjoying a lonely dinner when he hears a chilling noise that leads him to become the first casualty of the undead.
The following morning, Vegard embarks on a quest to find Sara, only to uncover the horrifying remains of the hiker. This harrowing search plunges him deeper into the wilderness, where he crashes through the snow and is knocked unconscious in a concealed cave. As night falls, Erlend stumbles upon an old wooden box brimming with wartime treasures, celebrating their discovery until one student pockets a golden coin, which is later returned to the box. Their merriment is abruptly interrupted when Erlend sneaks away to the outhouse for an intimate moment with Chris, who soon falls victim to the zombie horde.
As they scramble to find their missing friend, they come across Sara's abandoned backpack, a chilling reminder that the remnants of war continue to haunt the living. Upon emerging from the cave, Vegard is met with a gruesome sight: Sara's severed head alongside German military artifacts. His brief moment of respite is shattered as a zombie attacks, and in a desperate attempt to survive, Vegard fights back furiously. Utilizing an intestine as a makeshift rope, he escapes to solid ground, but not before he sustains severe injuries. Grabbing an MG 34 machine gun, he attaches it to his snowmobile with grim resolve.
Meanwhile, the remaining group—Martin, Roy, Hanna, and Liv—desperately scatter for survival. Martin and Roy attempt to divert the advancing zombies, while the women make a break for the vehicles. However, Liv's escape takes a horrific turn when she's ambushed and knocked unconscious by a zombie; she awakens to a gruesome fate as her intestines are yanked out by two attackers. In a final attempt to evade her gruesome end, she activates a stick grenade, taking out both zombies—and herself.
Hanna manages to outwit a zombie, sending it plummeting off a cliff with a well-timed kick of ice. Meanwhile, Martin and Roy unwittingly set the cabin ablaze with Molotov cocktails, forcing them to flee and grab power tools as makeshift weapons. Just as Vegard arrives, his machine gun blasting, they all strive to fend off the relentless wave of flesh-hungry zombies.
The relentless fight takes a steep toll: Vegard falls amid the chaos, and Martin, in a tragic turn of events, accidentally ends Hanna's life just as she returns to the cabin. As Martin prepares to confront Herzog, who commands an army of zombies, he suffers a terrible bite, prompting him to undertake a gruesome self-amputation with a chainsaw to stave off the infection.
When the dust begins to settle, Martin and Roy gather their courage to retaliate against Herzog, yet their effort is quickly thwarted as hundreds of zombies erupt from the snow—an unholy wave of death. In their desperate bid for survival, Roy meets a brutal fate at the hands of a hammer-wielding zombie, only to be disemboweled and ultimately killed by Herzog, who claims Roy's watch as a grim keepsake of this nightmarish ordeal.
