Halla is a fifty-year-old independent woman. But behind the scenes of a quiet routine, she leads a double life as a passionate environmental activist. Known to others only by her alias “The Woman of the Mountain,” Halla secretly wages a one-woman-war on the local aluminum industry. As Halla’s actions grow bolder, from petty vandalism to outright industrial sabotage, she succeeds in pausing the negotiations between the Icelandic government and the corporation building a new aluminum smelter. But right as she begins planning her biggest and boldest operation yet, she receives an unexpected letter that changes everything.