1987. A few days before Christmas, a severe snowstorm breaks out throughout Iceland. In the eastern part of the country, in a remote place, a middle-aged couple lives. In their isolated farmhouse, Erla and Einar prepare for the difficult night ahead. Until someone knocks on their door.

It is an uninvited visitor, a stranger who claims to have lost his way and seeks shelter in the storm. Despite the woman's reservations, they eventually allow him to come in. However, they will bitterly regret it because this particular man tells lies and hides his true identity well. When the power is cut off and everything is plunged into darkness, a real horror story begins. 

Later, Hulda Hermansdottir, the inspector of the Reykjavik Police, who is trying to overcome a personal family tragedy, takes on the investigation of the case and goes there, where along with the bodies awaits her a terrible, unsolvable mystery. In The Mist, Ragnar Jonasson, this wonderful storyteller, the new great star of Scandinavian noir, elevates his art.