Ida's Line tells the story of Ida Joubert, a young woman, coming of age during a period of growing racial hatred in Oudtshoorn, South Africa in the 1930's and 1940's. Ida openly rejects these racist views and challenges the prevailing patriarchal attitudes. This brings her into conflict with her white middle-class family. Matters come to a head when she falls in love with Rueben May, a mixed race teacher who wants to marry her.