When Evie's father falls desperately ill, she returns to the family home on Orkney, a wild landscape she left as a teenager, vowing never to return. Her arrival strains her relationship with her estranged sister Liv, fractured after a childhood trauma.

As Evie clears out her father's neglected house for sale, she feels isolated but is drawn to a group of cold-water swimmers led by her old friend Freya, who find peace beneath the waves. Together, they help Evie confront her past mistakes, revealing truths that alter the community and profoundly affect her family.