Olive Heriot and Hugh Manning had been in love for years but marriage had been out of the question because of the intervention of Olive’s mother. Now at last she was of age and due to gain her inheritance and the freedom to choose. A dinner party had been arranged at the Heriot’s home and Hugh expects to be able to announce their engagement. Things start to change after a gruesomely realistic game entitled “murder” which relies on someone drawing the Knave of Spades after cards are dealt. Tragedy strikes and other relationships are tested and consummated - but is this all real or imagined?