as a kid I used to love The Professionals, Bodey and Doyle going about their CI5 police business in a less than ethical manner.
Sir Ranulph Fiennes, the trans-global explorer, wrote an SAS novel called The Feather Men, re-issued as Killer Elite to coincide with the cinematic adaptation.
I loved Sir Ranulph's book, especially the last couple of chapters. The story was superb; gritty, involving, authentic. I enjoyed the film adaptation; they didn't fuck it up by trying to 'modernise' it, they remained properly faithful to the original 1980's material.
"You can't run away from who you are, Danny," his controller tells him.