In part 3 of "The Flood," Oracle faces off against the Calculator, while Batgirl is forced to team up with the Calculator's daughter in an attempt to save the citizens of Gotham City from a crippling techno-plague. But who will save Batgirl from an infected and rampaging Man-Bat? BATGIRL #12 hits 6/9, courtesy of writer Bryan Q. Miller and artist Lee Garbett.