I had read Palmer's RED CLAW a while back and loved that book so I'm not sure why it took me so long to read this next one.
It begins with Sharrock, a warrior whose planet is invaded by a more powerful force. Everyone is killed except for him-and he's transported to the inside of a massive spaceship that's set up to mimic a planet. It's there he meets other aliens in the same boat, including Sai-ias, an octopus-like creature who seems to be in control of the area. Sharrock learns that all the other aliens here cannot die because of something their captors have done to them-and that they'll be used to conquer other world just like how their own worlds were destroyed. There's different relationships between the widely differing aliens. Sharrock remains unwavering in his revenge against the creators of the "Hellship" and eventually convinces Shai-ias to join him in his purpose.
There's also the story of Jak, an entirely different alien species on a different ship. He eventually runs into the Hellship and is determined to destroy it, even if it takes thousands of years and traversing the multi-verse.
HELLSHIP is a very entertaining, unpredictable novel. And it moves fast-I think I read the 400+ pages in a week. Recommended.