BATGIRL AND THE BIRDS OF PREY VOL. 1: WHO IS ORACLE?

In these tales from BATGIRL AND THE BIRDS OF PREY #1-6 and REBIRTH #1, a mysterious new criminal operative called Oracle has declared war on Gotham City! Barbara Gordon, a.k.a. Batgirl—and a.k.a. super-cyber hero Oracle—in a previous guise, takes exception to someone smearing her legacy. Can she count on Black Canary and the volatile Huntress to help her get to the bottom of this mystery?