Wither

Gunnar searches for his daughter Lisa and finds his wife attacking her. He shoots his wife twice, killing her to stop the attack. The opening titles reveal the history of the Vættr, hinting at an ancient evil looming over the events to come.

A young couple, Albin and Ida, plan a weekend at a remote cabin with friends. As they travel, they notice Gunnar watching them from a cliff, and he is shouted away by the group led by Simon. The tension hints at a looming menace that will cross their paths.

The group reaches the cabin only to find the door locked; Marcus discovers an open window and lures Marie inside with encouragement. Marie climbs in and uncovers an axe, while an earth-like creature watches her from the shadows in the basement.

Marie’s sickness worsens as the party settles in and a tense mood grows. During a moment of mischief, Marie attacks Tove, bites her lip, and spits blood into Linnea’s eyes, signaling something supernatural at work. Gunnar arrives and explains the Vættr’s power to steal souls by eye contact, warning of undead slaves and infection.

Tove falls under the influence of the spreading illness and Marcus tends to her. Tove resurrects and ambushes Marcus, injuring him before Gunnar intervenes, though Tove escapes again. The infection quietly spreads through the group as fear mounts.

Gunnar goes out to kill Tove, but she ambushes and bites him. He overpowers her and decapitates her with a fishing knife, then takes his own life in the shed, leaving the remaining group to face the mounting horror alone.

Simon notices an infection in Linnea’s eyes and, overwhelmed by fear, beats her unconscious and buries her alive. The group’s cohesion shatters as fear triumphs over reason beneath the cabin roof.

Overcome with grief, Simon ignores orders and heads back to the cabin to try to save his sister Ida, realizing that lawful help is no longer likely to arrive. The rescue mission thrusts him back into the deadly trap.

Marie breaks free and the survivors fight to subdue her; Marcus dies during the struggle while Albin crushes Marie’s head with a rock. Marcus then rises as an undead and Ida and Albin retreat to an upper floor, seeking safety from the escalating chaos.

Simon arrives and attempts to help, but Marcus hurls him from a window. He survives yet is soon attacked by an undead Linnea, who stalks the cabin with the others now cornered by the rising undead threat.

Ida and Albin decide to escape; Ida’s cellphone helps map a way out while Albin retrieves the axe Simon had earlier. They prepare to move through the house’s precarious shelters, hoping to slip away while the undead threaten from every side.

Linnea is killed by Albin with the axe and Marcus dies after colliding with a table. Simon forces his blood into Ida’s mouth, but Albin shoots Simon dead to end the threat. Ida becomes undead, and Albin kills her with a heavy shelf. The Vættr rises from the basement, but Albin disables it by turning off the lights and dropping a fridge on it, crushing the creature. He leaves the cabin, now stepping into the role of the new Gunnar.