BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
Thrawn’s latest triumph still rests newly on his shoulders. Despite leading the Chiss to victory and bringing glory to the House of Mitth, the true threat to the Ascendancy has not yet been extinguished. Their foes do not send threats or ultimatums, or mass ships on the edge of the Chaos. Their weapons come cloaked in smiles and generosity—gifts offered freely, services granted unconditionally.
Across the Ascendancy, seemingly inconsequential events could herald the doom of the Chiss. As Thrawn and the Expansionary Defense Fleet rally to uncover the enemy plot, they discover a chilling truth. Rather than invade Chiss capitals or pillage resources, this mysterious enemy strikes at the very foundation of the Ascendancy by widening the rifts between the Nine Ruling Families and Forty Great Houses below. As rivalry and suspicion sow discord among allies, each warrior must decide what matters most: the security of their family, or the survival of the Ascendancy itself