The Superman Family #173

Jimmy accompanies Superman on a mission in Kandor to help Dev-Re, but they bring along an uninvited guest. Dev-Re, who knows Superman and Jimmy are Nightwing and Flamebird, asks them to find his daughter Sarna, who has fallen in with a group of violent radicals. But the space-germ that followed them spreads a plague throughout Kandor, causing the populace to attack the heroes, which allows Sarna to knock out Jimmy. Jimmy tricks Sarna into using her group’s explosives to blow off the top of the bottle, instantly making the Kandorians invulnerable and reversing the effects of the plague.