Sofie (Laura Østergaard Buhl) and her mother Tove (Ann Eleonora Jørgensen) travel to her grandmother's (Vigga Bro) for Christmas before they move to Singapore for Tove's new job. When they arrive at Grandma's, Sofie meets the new family that's moved in on the second floor. She and the new boy Jonas (Lukas Schwarz Thorsteinsson) become friends and discover a secret cave out in the woods. In the cave they find a chained man (Martin Brygmann) who claims he's the Norse god Loki (Loke in Danish). He grants the children three wishes if they'll remove his chains. The children accept, but they are unaware that by doing so, they have just started Ragnarok: the end of the world. In the cave they find a portal which leads to Valhalla, where the Norse gods live. Will Sofie and Jonas stop Loki before Ragnarok breaks loose and the other gods find out what they've done?