John Milton is trying to make amends for a career spent killing for the British Secret Service. He has a burning need to right wrongs - and rewrite his own bloody past. He finds himself in Louisiana - the Big Sleazy, the bayou, and the post-Katrina wreckage of the Gulf Coast - with a debt of honor to repay. Isadora Bartholomew, who saved his partner's life, needs his help. Joel Babineaux, a ruthless property magnate, is out to sink the charity she established to help rebuild the Lower Ninth Ward. Just when Milton thinks he has neutralised Babineaux's scheming, a dangerous man from his past...

John Milton is a former assassin for the British government. He is a ronin, trying to atone for his past sins by offering his services to those people who have no-one else to whom they can turn. Milton is keeping a low profile in London when he meets Eddie Fabian. Fabian confesses that he is considering suicide, and that the reason for his depression was the abuse that he suffered as a child. Milton offers to help, but, before he can, Eddie is found dead in circumstances that Milton considers suspicious. And then events take a turn that no-one could have anticipated... Milton's attempted good...