In Assassinanny 911 Brock was contacted by his handlers in order to find Hunter Gathers. Gathers had gone A.W.O.L with forty million dollars of the OSI's money and a plastic surgeon kidnapped from "the enemy". Brock is dispatched to an island in Micronesia in order to take Hunter out permanently.
Upon reaching Hunter's lair, Brock finds his old mentor unconscious on a table with the plastic surgeon standing over him. Before Brock can kill Hunter, the surgeon stops him, reading him a letter from the Colonel explaining that he's tired and wants out of the life. Brock takes no heed and lifts up the sheets covering Hunter. He's shocked to discover the Colonel's undergone a sex change operation. Remembering Gathers' directive, "No women, no children. It's what separates us from the baddies." Brock leaves her to live, but only after double checking her lower half just to be sure.
Hunter displayed, in numerous flashbacks, a tendency to cross-dress as a woman whenever going undercover. However, both as a transvestite and later a transsexual, Hunter still makes no effort to appear feminine, continuing to display a rough whiskered face and a deep macho voice.