It is 1950, the League of Nations has collapsed and the newly formed United Nations has rejected all those who worked and fought for the League. Edith Campbell Berry and her now husband Ambrose Westwood are back from one of the oldest cities of the world to live in the newest city of the world - she had moved from trying to make a world capital in Geneva to a dusty town trying to become a national capital. Edith has ambitions to be Australia's first female Ambassador and is seeking a position in Canberra with the Department of External Affairs. Finding her ambitions thwarted in this area Edith vigorously involves herself in the building of the new centre of civilization. Frederick, Edith's brother, who disappeared from her life before she left Australia, reacquaints himself with her and introduces Edith to the Australian Communist Party in which he is a leader. Frederick's relationship to Edith, in the time of the Communist Party Dissolution Act is a threat to Ambrose's career with the High Commission, or does it provide him with an opportunity to spy? After pursuing the Bloomsbury life for many years, Edith now finds herself questioning her sexuality and why she has been prepared to settle for being 'a wife with a lavender husband' and yearns for a family. Richard, who audaciously laid his hand on her leg at a dinner party hosted by Prime Minister Menzies, ultimately fulfils these desires by marrying Edith and providing her with two step-sons. Uranium has been discovered in Australia and Richard is involved in its study and exploitation. Atomic energy has always been an interest of Edith and she takes a role on the Uranium Desk - which she re-names for her own purposes the Atoms for Peace desk - at Parliament House. Cold Light completes the circle begun in Grand Days, the search for symbolic sites to achieve great civic enterprises.