When Evie's father falls desperately ill she finally returns to the family home on Orkney and the wild landscape she left as a teenager swearing never to return. Not everyone is happy at her arrival particularly her estranged sister Liv their relationship broken after a childhood trauma. As Evie clears out her father's neglected house to prepare it for sale she finds herself drawn to a group of cold-water swimmers led by her old friend Freya who discovers calmness beneath the waves. Together they help Evie face up to the mistakes in her past unlocking a treasure of truths that will reverberate through the community and shake her family to its core.