A cryo-ship drifts through the vast interstellar distances at sub-light speeds, cared for by a patient AI. Their destination is a planet just waiting for colonists to arrive; or at least, it HAD been waiting for colonists to arrive.
Unfortunately for the frozen crew, faster than light travel was discovered some time after they departed the Earth, and their once-empty destination is now home to a thriving population that has colonized and grown prosperous, served the Earth Empire, grown dissatisfied and declared independence during the ship’s long flight.
Even more unfortunately, they haven’t forgotten about the ship or its eventual destination. And they’re prepared…