In 1936, twin brothers return to Britain from the Berlin Olympic Games with bronze medals and a young Jewish woman, a refugee from the Nazis, concealed inside their van. This act of compassion sets in train a sequence of events which has the potential to change the course of history.
Soon the brothers' bond is broken apart by their rivalry for the girl, and the first of many separations takes place. World War II is looming, but the brothers take different paths: Jack becomes an RAF pilot, Joe, a conscientious objector, works for the Red Cross.
Five years later, in Britain's hour of greatest danger, an opportunity for peace unexpectedly arises. A larger separation, a dividing of the ways, becomes a real possibility. Which of the brothers is to stride briefly across the stage of history?