Musical melodrama set in Liverpool about twins separated at birth and the effects on their personalities as they grow up of 'nature' and 'nurture'. A poor family, already with kids, is blessed with twins, but they can't cope. The mother cleans at a 'posh' house where they are desperate to have kids but can't and a deal is struck which no-one must know about. Despite the efforts of the new family the boys paths cross time and time again as they grow and one becomes 'bad' while the other is 'good'. Eventually they clash with tragic consequences. The musical is un-usual in having a "narrator" who helps to move the plot along.