Started great but couldn't keep up the pace

This story suffered for its length.
It started fast and furious, our two heroes captured by insect-like aliens but while the action scenes sped along I was confused by the backstory between our MCs -- they obviously had history, possibly were only pretending to hate each other. I didn't think this was suitable explained. Then when they finally had a moment to connect I thought certain things came from out of the blue, not the attraction, because while I didn't really feel it, I knew it was supposed to be there. But Gavnson's feelings of worthlessness and the depth of his feelings for Norland seemed out of place. Also I wasn't convinced Norland wasn't doing it just because Gavnson claimed he couldn't recover on his own. Plus that whole scene where they 'talk' read as very stilted and forced. Nobody talks like that, not even aliens.
All in all, started great but couldn't keep up the pace.
I think I'd like to read the sequel to see where the author takes these guys.