In London's 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, Superintendent Thomas Pitt is as certain as he can be that one of the three deeply devout men in the house committed murder. Could it have been the Reverend Parmenter? His handsome curate? Or his son, a fervent Roman Catholic? Pitt and his clever wife, Charlotte, refuse to settle for less than the truth'or less than justice.