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.
The alien Yuuzhan Vong have launched an attack on the worlds of the Outer Rim. They are merciless, without regard for life—and they stand utterly outside the Force. Their ever-changing tactics stump the New Republic military. Even the Jedi, once the greatest guardians of peace in the galaxy, are rendered helpless by this impervious foe—and their solidarity has begun to unravel.
While Luke struggles to keep the Jedi together, Knights Jacen Solo and Corran Horn set off on a reconnaissance mission to the planet Garqi, an occupied world. There, at last, they uncover a secret that might be used to undermine the enemy—if only they can stay alive long enough to use it!