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.
Galactic espionage hits the Empire—hard!Haarkon Dak has been undercover in the Imperial bureaucracy for years......but now, he's the only chance to save Rebel sympathetic senators!