Prison Planet — William C. Dietz

Convicted of a crime he did not commit, Jonathan Renn is sentenced to life in the Swamp, a prison-planet death row in a distant galaxy. Renn only has two choices: Escape the Swamp or die in the process. Defending himself from attacks by deadly, native monsters and his fellow convicts, Renn is obsessed with escaping the planet and getting his revenge on the people who set him up. Marla Marie Mendez is even more down on her luck. Trapped inside a cybernetic dog and dropped defenseless into the Swamp, Marla can only rely on Renn and her claws to save her from the unfriendly elements. They must find a way out of the Swamp—and quickly—before their life sentence is cut short.