Marion Kerrison, who is beginning to make a career for herself at the Bar, where women have only recently made their mark, is given the defence brief in a notorious murder case. From the very start she has her own theory of the crime, but this does not easily accord with the evidence of witnesses or even with that of her client, the accused. Through all the dangers and disappointments of the trial she pursues her own vision of the truth. It is her character that is at the core of the book. Her impulsiveness and courage, her insight into facts and the hearts of witnesses, together with her own position as a woman in a man's stronghold, provide the motif of dual struggle that leads inevitably to the brilliant climax.