The Eternal Prison (2009) is the 3rd book in the Avery Cates science fiction series by Jeff Somers. I loved the first one. I wasn't disappointed in the second one, but didn't like it as well as the first. I liked this one less. I'll cut my losses and not seek out the rest of the series, but I'm glad I've read these.
from the back of the book:
Avery Cates is a wanted man.
After surviving the worst bioengineered disaster in history,
Cates finds himself incarcerated -in Chengara Penitentiary.
As Chengara has a survival rate of exactly zero, the System's most
famous gunner must do some serious plotting. And a betrayal or
so later, he achieves his goal. At a price.
All he has to do next is defeat some new personal demons,
forge some unlikely alliances, and figure out why the people he's
killed lately just won't stay dead. Plus pull off the biggest
assassination of his career...
SF Revu calls the prose "inelegant but articulate" but has a positive review.
I've also read these in this series: