It’s another full length classic tale by Hamilton, Swan and Klein in Superman 158 (Jan. 63).
Super-powered thieves appear in Metropolis, men who not only can go toe to toe with Superman, but also know him, and have a grievance against him. Superman recognizes some of them, as being from the bottle city of Kandor.
Bringing Jimmy Olsen with him, for no particular reason, Superman heads to the Fortress and they descend into Kandor. Superman runs into Nor-Kann, a friend of his father’s, who informs Superman of how Than-Ol has made the Kandorians comes to blame Superman for their captivity, and how he intends to enlarge the city, despite the risks.
With everyone hating him, Superman decides to adopt a disguise for his time in Kandor, and figures Jimmy should have one as well. They name themselves after two Kryptonian birds, the Nightwing and the Flamebird. But really, they are patterning themselves on Batman and Robin.
Superman also enlists the help of Van-Zee and the Superman Emergency Squad. Van-Zee looks identical to Superman, and allows the hero to impersonate him. Sylvia, Van-Zee’s human wife, who looks identical to Lois Lane, has a cameo.
Superman’s impersonation gets exposed, and Van-Zee dons the Nightwing costume to aid Jimmy Olsen in freeing Superman, but the two wind up getting sent into the Phantom Zone.
Superman gets him and Jimmy out of the Zone, but not before Than-Ol manages to get Kandor out of the Fortress, and enlarges it.
But as Superman knows, the enlarging process makes the atomic bonds unstable, and the city begins to disintegrate. The Kandorians will as well, but Superman shrinks them all, and puts them back into the bottle.
Early in, the Kandorians had torn down a statue of Superman. But at the end of the story, grateful that he saved their lives and city, a new pair of statues are erected, to Nightwing and Flamebird.
Nightwing and Flamebird will go on to a long life, with many variations, over the years. Van-Zee will take over the identity for quite a while in the 70s, before Dick Grayson adopts the name after shedding the Robin identity. Playing off of that, Bette Kane, the first Bat-Girl, would get re-chirstened Flamebird. A completely different version of the pair would go on to a run in Action Comics shortly before the New 52.