This Gulf of Time and Stars — Julie E. Czerneda

To save their world, the most powerful of the Om ray left their homes. They left behind all memory of their past. Calling themselves the Clan, they settled among Humanity, hiding in plain sight, using their ability to slip past normal space to travel where they wished, using their ability to control minds to ensure their place and security.

They are no longer hidden.

For the Clan face a crisis. Their reproduction is tied to individual power, and their latest generation of females, Choosers, are too strong to safely mate. Their attempt to force others to help failed until Sira di Sarc, their leader and the most powerful of their kind, successfully Joined with a human, Jason Morgan, starship captain and telepath. With Morgan, Sira forged the first peace between her kind and the Trade Pact.

But it is a peace about to shatter. Those the Clan have controlled all these years will rise against them. Her people dying around her, war about to consume the Trade Pact, Sira will be left with only one choice. She must find the way back. And take the Clan home.