In affluent Brunswick Gardens the battle over Charles Darwin’s revolutionary theory of evolution intensifies as the respected Reverend Parmenter is boldly challenged by his beautiful assistant, Unity Bellwood, a “new woman”, whose feminism and aggressive Darwinism he finds appalling. When Unity, three months pregnant, tumbles down the staircase to her death, Pitt is certain that one of the three deeply devout men in the house has committed the murder, but which one!