Mary Boyne, who made shirts at four dollars a week, had no place for love in her life - only despair and hate for the son of the man who had plunged her family into deepest distress. Peter Kenwitz loved Mary, but because he was a mathematician and a pessimist by trade, his love was as hopeless as her chance for happiness. Dan Kinsolving was the son of the man who ruined Mary's family. He loved Mary and gloried in her hatred for him. He set about moving the problem of turning her hate into love. He let X represent The UNKNOWN QUANTITY in life's greatest problem. Did he win?
taken from a newspaper ad for The Unknown Quantity