In a small estuary village on the Welsh coast, Catrin is mourning the anniversary of her mother's drowning when a teenage girl disappears on the same mudflats. Terrified of history repeating itself and driven by unresolved grief, Catrin becomes obsessed with finding Emily. Her search dredges up secrets from the village's past and present, uncovering far more than the missing girl.

This is a story of lost women – some who can be found again, and some who can't.