The Jupiter-Three Dilemma

Former star ship commander, Captain Benjamin David Grayling, is in trouble. His outspoken views on the criminally despotic leadership of the United Coalition of Planets have resulted in his life-exile to Draxos-III, the planetary home of an infamous penal colony where a prisoner's life is no longer his or her own and where life or death can depend on the whim or fancy of the completely unaccountable and seriously dysfunctional colony guards, some of whom are not even human.
Enter the Forlorn Hope, once the very last hope of freedom for the former native inhabitants of Draxos-III and which has now been rescued from its century-long abandonment in deep space and refurbished by military engineers and archaeologists to its original, awesomely powerful, specification. Now, with the rebuild complete, can the highly-skilled and brilliantly capable former star ship commander steal the ancient vessel and use it to turn the tables on his universally feared and loathed captors? Further, if he can, could it then be possible for him to assist the return of a more decent and humane system of government to the long-since subjugated peoples of the many planets of the, hitherto, much-feared Coalition?