The forty-two year old hitman Arthur Bishop is frequently hired to kill without a trace and he carefully studies the profiles of his victims to find the perfect and clean way to execute them. When he is hired to kill "Big" Harry McKenna, who was a former friend of his father, Arthur meets his son Steve McKenna asking for money to Harry at home. Later in Harry's funeral, Steve asks for a ride to Arthur and they become very close. Arthur finds potential in the twenty-four year old Steve to become a professional killer and he invites the youngster to form a partnership with him. However his attitude displeases the powers that be and Arthur is sent to Naples to kill a mobster. Arthur finds a file about him in a drawer at Steve's house but he invites Steve to travel with him to Italy. Soon they learn that someone wants them to see Naples and die.
