Multiple heroes
 
Dr. Rhea Landon knew she'd been thrown into Phobos Prison to die. The most  notorious prison in the solar system and one from which there was no escape,  Phobos Prison housed the most dangerous predators in the solar system—and the  few who survived more than a year were the worst of the worst.  Dragged into the arena where the warden held 'gladiator' games for the  entertainment of the staff and inmates, she was stripped naked and chained to a post.