There's a new hero in Old Gotham. A Golem creature has been fighting back against armored criminals attacking local businesses. Tracking the creature down to an abandoned synagogue, Batman and Katana discover that the "Golem" is actually Rex Mason (aka Metamorpho), who's been retraining his body in order to help the citizens of Old Gotham. Realizing he's found a new ally, Batman joins Metamorpho's fight, but it isn't easy. The criminals are using high-tech weaponry... from Stagg Industries!