The insidious ease with which fate elevated Mary Stuart to the pinnacle of earthly power has hardly ever led to such a tragic end. Six days old - Queen of Scotland, at seventeen - Queen of France, she knew all the joys of triumph. And at twenty-three, everything was sacrificed to the awakened all-consuming passion, which deprived her of the crown and freedom (from the age of twenty-four she will spend all the remaining years in prison).