Now consumed by vengeance, Bannion quits the force, which he now realizes is being controlled by the mob, and enters the dark corridors of standard noir fair, cheap hotel rooms, slick night streets, and run-down bars (this one called The Retreat); in short he himself becomes a kind of criminal, at one point, in yet another visit to Mrs. Duncan, nearly strangling her. Her death, in fact—which would result in a release of the letter and the downfall of the mob world—will ultimately be necessary for Bannion’s redemption.
Spotted with Bannion, Debby is soon after punished by Stone, as he throws a pot of boiling coffee into her face, disfiguring half of it forever—symbolizing, once more, Lang’s perception of the dual nature of human beings, and, in particular, of Debby who, as Bannion taunts her, gets “her money from a thief.”
Finally, in remorse of her life, Debby visits Mrs. Duncan, suggesting that both of them are “sisters under the mink”—women willing to sell themselves in order to wear the mink coats in which they are both dressed. She kills the woman, resulting in the series of events that finally reveal the truth, that Mrs. Duncan has kept her husband’s letter, which revealed Lagana’s involvement with the police and city government—in order to blackmail Lagana for regular payments.