It's thirty years since the collapse of the Gulf Stream and the arrival of the tsunamis from La Palma and the Eriador Ridge off Ireland's Continental Shelf that created Iceapelago; thirty islands that were once Ireland.

The survivors struggle in pre-medieval conditions to secure food and medicines ahead of Winter Day when tundra conditions lock down Iceapelago for months on end. The Commander, the titular head of Iceapelago, tries his best to manage rising dissent and dissatisfaction. He is supported by some but not all of the elected leaders, the Sixes and Sheriffs from the islands.

An Arctic storm that arrives on the eve of Winter Day causes havoc.