Akureyri, Northern Iceland, 1983. High up in the most northern part of Iceland stands the Akureyri Sanatorium. Once a hospital dedicated to treating tuberculosis, it now sits haunted by the ghosts of its past. One wing of the hospital remains open and houses six employees: the caretaker, two doctors, two nurses and a young research assistant. Despite the wards closing decades ago they remain at the hospital to conduct research. But the cold corridors, draughty windows and echoey halls are constant reminders of the building's dark history. When one of the nurses, Yrsa, is found brutally murdered, they discover that death has never left this place - and neither did its secrets.