To Guard Against the Dark — Julie E. Czerneda

The final book in the hard science fiction Reunification trilogy, the thrilling conclusion to the award-winning Clan Chronicles

Jason Morgan is a troubling mystery to friends and enemies alike: once a starship captain and trader, then Joined to the most powerful member of the Clan, Sira di Sarc, following her and her kind out of known space.

Only to return, alone and silent.

But he's returned to a Trade Pact under siege and desperate. The Assemblers continue to be a threat. Other species have sensed opportunity and threaten what stability remains, including those who dwell in the M'hir. What Morgan knows could save them all, or doom them.

For not all of the Clan followed Sira. And peace isn't what they seek.