The day before Edwina Black's funeral, Inspector Martin calls to interview her husband Gregory, her companion Elizabeth and her housekeeper, Ellen. Gregory has long endured the domination of his wealthy wife, but is in love with Elizabeth. It is revealed Edwina died from arsenic. Gregory and Elizabeth quarrel bitterly. However Ellen confesses that Edwina poisoned he'self: with vindictive spite she devised a suicide which would serve to incriminate Gregory and Elizabeth and so destroy them.