When Superman leaves Earth for New Krypton, he appoints Mon-El, newly freed from the Phantom Zone, to take his place as guardian of Metropolis.
Kryptonians Chris Kent and Thara Ak-Var become the superheroes Nightwing and Flamebird on Earth and are being hunted by Ursa.
The mission of the two superheroes is to hunt down Zod's sleeper agents on Earth and return them to the Phantom Zone.
The next mission of the Kryptonian duo deals with taking down Nadira Var-Em and Az-Rel, who are described as Krypton's equivalent of Bonnie and Clyde.
This ends with Nightwing and Flamebird losing the track of the two criminals, who are held captive by Sam Lane.