At one time there was a possibility that I might write a third novel, making it a trilogy. That isn't likely to ever happen, and the story is complete without it.
The two novels are:
The unwritten third novel was to have been called The Exile and the Empire.
I had also thought about writing other stories set in the same universe, but following other characters; one of these, entitled Werewolf, was abandoned when I realized it was more or less the same story as Eric Frank Russell's Wasp.
At present, I don't expect to write any more of these, but you can still read these two; follow the links for details.
Covers of the original, long-out-of-print Del Rey editions:
Cover art by David Mattingly
Cover art by Darrell K. Sweet
That's it; here's your list of handy exits: