The series takes place in Iceland, after the subglacial volcano Katla has been erupting constantly for a whole year, Gríma is still looking for her missing sister who disappeared the day the eruption started. As her hope of ever finding her body is fading, the residents of the surrounding area start to have visits from unexpected guests. There might be something hidden under the glacier no one could ever have foreseen. Speaking about the score, Högni says: "when I was asked by Baltasar [Kormákur] - the director and show creator - I started writing so when the filming was finished, I had already written a number of pieces for the show. As relatively in-experienced in the field I imagined that my work was finished and the rest was a matter of post-production and music editing. However it immediately became clear that my ambitions and the nature of the project called for second, third and fourth wind in order to fulfil the auditory architecture that needed to be built". Realising it was a monumental task, Högni kept a strict schedule every day, starting by writing and arranging in the morning, recording and mixing in the afternoon and presenting to the producer each evening. The score was recorded in Högni"s own studio, where him and his collaborators consisting of Tóti Gudnason, Inga Magnes, Petter Ekman, _órunn Osk and Sigurgeir found themselves working in a completely different way than they"ve done before, due to the nature of the project - "we worked the music out of my studio in Reykjavik, where a healthy number of musicians rotated through at the pace of an average ice cream parlour on a long summers evening in Reykjavik. The urgency of delivering cues and material left one in the state of instinctual execution at all hours without hesitation".