Giovanni Falcone & Paolo Borsellino

It is perhaps a uniquely Sicilian sort of irony that an easygoing smile shared by two old friends would come to symbolize the island's darkest hour of the past 60 years.

The parallel destiny of Palermo prosecutors Giovanni Falcone and Paolo Borsellino began and ended in Sicily's capital, where the two were born — and killed in 1992 in successive Mafia bomb assassinations. In between, the pair nearly brought Cosa Nostra to its knees with a new methodical approach, as brilliant as it was brave, to unlocking the Mob's code of silence.

And so that...