"Will the Last One to Leave Mercury Please Close the Planet?"
The Legion arrive on Mercury to solve a mystery surrounding Karate Kid, only to find another mystery of vanishing staff and patients from the Medivac center. It falls to the combined talents of Chameleon Boy and Sun Boy to crack the puzzle, but not before the team come close to perishing on the infernal surface of Mercury.
"A World for the Winning!"
Superboy, Element Lad and Colossal Boy assemble with a host of United Planets dignitaries to greet the arrival by starship, of delegates from the planet Corvan IV. They are initially shocked when Mano and the Persuader emerge from the ship, and further shocked when it's apparent that they are in fact the delegates.
The pair explain they are petitioning for their adopted home to become part of the United Planets. The trio of Legionnaires visit Corvan IV where they meet with the other remaining members of the Fatal Five; Tharok, Validus and the Emerald Empress.
After a tour of the planet, it is decided that the Fatal Five's influence on the culture and technological progress of the native Corvanians is detrimental. The Legion intend to recommend a rejection of the appeal to join the United Planets, but the Five revert to type and lash out with a lethal assault. Only Superboy manages to escape in time to warn the rest of the Legion.