Badge of Infamy (version 2)

Set in the early 22nd century: Dr. Daniel Feldman, stripped of rank and status and named pariah for violating Medical Lobby rules, stows away on a spaceship and flees to Mars Colony. There, while essentially practicing medicine without a license, he stumbles upon a plague organism indigenous to Mars, that threatens the whole colony and potentially the human race. Performing research to identify a cure, (also in gross violation of Medical Lobby rules) he must risk his life to buck the entrenched