Although circumstantial evidence is damning Leonard Vole convinces even the perceptive Sir Wilfred that he is innocent of murder. In the mounting tension of the trial there are three major developments. First Vole’s wife takes the stand and coldly swears away her husband’s alibi. Second a brassy young woman sells letters to Sir Wilfred that prove that Mrs Vole has committed perjury so as to dispose of her husband. Only then does Sir Wilfred discover how this acquittal engineered by Mrs Vole. Even then there is a dramatic finale.