Star Wars: Thrawn Ascendancy : (Book 1: Chaos Rising)

Beyond the edge of the galaxy lies the Unknown Regions: chaotic, uncharted, and near impassable, with hidden secrets and dangers in equal measure. And nestled within its swirling chaos is the Ascendancy, home to the enigmatic Chiss and the Nine Ruling Families that lead them.

The peace of the Ascendancy, a beacon of calm and stability, is shattered after a daring attack on the Chiss capital that leaves no trace of the enemy. Baffled, the Ascendancy dispatches one of its brightest young military officers to root out the unseen assailants. A recruit born of no title, but adopted into the powerful family of the Mitth and given the name Thrawn.

With the might of the Expansionary Fleet at his back, and the aid of his comrade Admiral Ar’alani, answers begin to fall into place. But as Thrawn’s first command probes deeper into the vast stretch of space his people call the Chaos, he realizes that the mission he has been given is not what it seems.
And the threat to the Ascendancy is only just beginning.