Mr. Z returns as Ordway, Janke, Grummett and Hazelwood begin the Blackout story arc, which runs through the other Superman books before concluding in the next issue of this comic, in Adventures of Superman 484 (Nov. 91).
Mr. Z is on the trail of his magical gemstone, and seeks out Emil Hamilton, after seeing press reports linking him to Superman. He uses some mind-control on Hamilton, and learns about a helmet he has created to see through Superman’s eyes when Superman needs to work on something and Hamilton cannot be there. Mr. Z alters the machine so that he can see into Superman’s mind.
Taking control of Superman, he sees that the hero has the gemstone in his Fortress, and together they leave to head there.
Once Mr. Z is gone, Emil regains control of himself. Lois Lane gets involved, and together they figure out what Z’s plan is. Emil thinks he can short out the helmet, but needs more power than he has. They link into the main electrical grid.
But Emil’s plan backfires in so many ways. Both Superman and Mr.Z are affected by the electrical charge, leaving them plummeting to Earth, while the entire city of Metropolis gets blacked out.
The story continues in the next issue of Action.