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.
Darth Tyranus has placed a bounty on the head of Hurlo Holowan, the diabolical droid engineer. But Holowan has fled to her fortified estate on Kuat. Getting into her headquarters is going to be difficult. Getting out is going to be tougher. Only a shapeshifter could hope to enter. Only a bounty hunter named Zam Wesell could hope to exit…alive.