After the death of her parents, ten-year old Mavis Donnelly becomes a pawn in a bitter custody battle between two families; her paternal grandparents, the socialite Donnellys of San Francisco, and on her mother's side, the Allegnas, an equally powerful family headed by Carlo Allegna, an upper echelon member of a New York crime family. Tom and Margaret Donnelly win the custody case in California when a judge declares the Allegnas unfit guardians. Carlo Allegna eventually triumphs over Margaret Donnelly through blackmail.Stunned over her weakness in sleeping with the crude mobster, Margaret outsmarts Carlo again and again with the help of Rudy Markov, a paid mercenary. In a murderous rage, Carlo heads to California to retaliate when his car is involved in an accident leaving him at death's door. Thoughts of revenge sustain him through painful therapy, his thoughts centered on destroying the Donnellys.Just before high school graduation, Mavis learns of the vendetta. Feeling guilty over the numerous tragedies, including her grandfather's fatal heart attack, she flees San Francisco. Once settled in Chicago, Mavis comes to understand the intricacies of two plots and wonders if she has become a replica of her vindictive grandmother.