Eccentric tycoon Jasper Whyte hosts a dinner at his mansion and announces that he will divide his money and give each guest a million dollars before the stroke of midnight. When his long-lost granddaughter suddenly arrives, Whyte changes his mind and proclaims that she will receive his entire fortune. A second lady appears at the estate, claiming that she is actually Whyte's granddaughter, Doris Waverly, and the first woman is found murdered in her room! With each guest possessing a motive, the mystery of the killer's identity briskly unfolds through a stirring series of surprises.