A Melbourne private detective, Mr. W., is called in to investigate the sudden change in a piggish solicitor's wife after she has been home to Preston to visit her family - her drunken actor father and sisters. She was a Roman Catholic and a former ballet dancer but was forbidden when married to see her family again. She dies on the visit with her new-born child and her twin sister impersonates her - but when all is discovered and she repudiated she and her father take murderous revenge. Suicide follows her father's desertion. (PB)