Cesare Cardinale is a rich businessman and race driver who also works as a hitman for the Mafia, because he enjoys killing. But after killing four would-be-witnesses, the Mafia bosses are afraid he might talk, so they want him dead.
The plot is a standard hitman story without any surprises. The focus is more on Cesare's romantic affairs than on the actual Mafia/hitman story. The book also spends quite long parts on background stories on the two female characters. "Stiletto" is a quick read, but not very interesting.