Apologies for the somewhat keywordy title, hopefully it'll help someone.
I'm embarassed to say - I lost this story *more than once*.
It start off with a scene from before the birth of the protagonist, where a strand of elder race DNA mixes in a drop of water, gets drunk (by accident) by his mother and thus she gives birth to an 'elder race' child.
The mother (and father) are murdered by the Evil Empire and the child is raised in a .. school where he has the usual old sensei.
Except the old sensei is also a member of this elder race and kidnaps the young man.
They steal a ship and go towards a planet where they recover a long-dormant ship from the elder race.
In the meantime, a girl from a space community of 'wanderers' who also looks for artifacts of the elder race (and who has one of their ships, albeit only partially activated, as their main base) ALSO finds the ship - and is therefore along for the ride when the ancient ship leaves the planet.
The story stopped with them leaving the planet and obliterating a ship of the Evil Imperial Forces just to make a point - at the time I last found it.
Any idea?
Thank you!