Kate is a twenty-six-year-old riddled with anxiety who works for a local paper in Brixton, London, covering forgettably small stories. Assigned to write about the closing of the local lido (an outdoor pool and recreation center), she meets an eighty-six-year-old widow who has swum there daily since she was a child. Kate's simple local interest story soon blossoms into a portrait of a singular woman -- and a beautiful friendship that provides sustenance to both women as they galvanize the community to fight the lido's closure.