The Middle of Nowhere: Star Wolf Trilogy

The Morthans were physically and mentally superior. Descended from humans, they were now, literally, “more-than" human … and considered the human race to be little better than animals. They would stop at nothing to conquer the remaining human-controlled worlds.

Docked for repairs after a harrowing battle with a Morthan ship, Jonathan Korie and his crew discover they have a Morthan imp aboard—a Morthan weapon so quick they have no chance of catching it, so clever they have no hope of outsmarting it and so deadly they have no choice but to try.