The Dark Knight stories tying into ZERO HOUR are now collected in their entirety. Time is collapsing upon itself! The villainous Extant has ushered in a series of black holes that are swallowing the universe, past, present and future! And like everyone else in the DC Universe, the Bat-family has seen time loops affect their lives. The result? The return of Barbara Gordon, Batgirl! Collects BATMAN #0 and 511, BATMAN: SHADOW OF THE BAT #0 and 31, DETECTIVE COMICS #0 and 678, CATWOMAN #0 and 14, BATMAN: LEGENDS OF THE DARK KNIGHT #0 and ROBIN #0 and 10.