In this ambitious, dramatic, and expansive tale of multiple generations of a Jewish Hungarian family, director Istvan Szabo (Mephisto) covers the end of the monarchy, two world wars, the 1936 Berlin Olympics, the concentration camps, the iron rule of Stalin, the Hungarian Revolution of 1956, and the fall of Communism. The screenplay by Szabo and American playwright Israel Horowitz charts the ways in which many of the characters tarnish their souls through the decisions they make. Despite the warning of the family patriarch, "Never forget who you are," his male offspring are attracted to power, prestige, and the lure of politics. Again and again, however, they are drawn back to the significance of three family talismans: a recipe book, a watch, and a photograph of a young woman in a moment of unguarded spontaneity.

The patriarch of the Sonnenchein clan is Emmanuel (David de Keyser), who as a 12-year-old went off to Budapest and built a successful business around "Sunshine Tonic." He is a deeply devoted Jew who tries to pass on the moral legacy of the faith to his children. But his two sons and adopted daughter are more interested in being assimilated into the Christian culture of Hungary. They all change their names to "Sors." Later his grandson converts to Catholicism in order to become a member of an elite fencing club that doesn't accept Jews. Emmanuel's great-grandson eventually changes his name back to Sonnenchein after becoming disillusioned with Communism.

Ralph Fiennes plays three of these characters. Each man has a rocky road in his relationship with a women — one marries his cousin, Valerie (Jennifer Ehle); another is seduced by his brother's wife (Rachel Weisz); and the last one has a dangerous and unfulfilling affair with the wife (Deborah Kara Unger) of a Communist Party leader.

At the heart of Sunshine is the character of Valerie, a free-spirited soul who becomes a photographer. She is there to support her son when he wins a medal in the 1936 Olympics. And when her grandson Ivan needs her, she is a source of moral support for him. Rosemary Harris plays Valerie in her later years and in nearly every scene she is in, radiance shines through vividly as a sort of spiritual incandescence. Ivan, who is the narrator of the film, at last comes to realize that the family legacy is not in the recipe for tonic but in his grandmother's indomitable spirit of freedom, which resides in her love of life, beauty, and the wildness of the natural world.