Marple is invited to the wedding of a friend, but the gaieties are interrupted when a stranger arrives; he provides the missing evidence which proves that the black sheep of the family, Jacko, was wrongfully hanged for murder. This raises the question of who in the household did kill the cold-hearted mistress of the house two years previously. As usual, Miss Marple is needed to uncover the hatred, jealousy, lust etc. behind the family's facade and sort out the threads of the mystery.