Dorfman, Andru and Esposito take their storyline up a big notch with the second chapter, in Action 363 (May 1968), with a superb Adams cover.
We learn that the ventriloquist who has hypnotized Clark Kent has also purchased a serum from Lex Luthor. This is Virus X, a horrible Kryptonian version of leprosy. This is what Clark is to use to kill Superman.
Clark Kent breaks into his own apartment, and spills the serum on himself. It takes effect immediately, though at first it only turns his hands a leprous green.
Superman quarantines himself, but Luthor makes a broadcast, revealing that Superman has been infected with Virus X. No one is sure if it can be passed to humans, but a cat brushes up against Superman, and catches the plague.
Superman is dressed as Clark when the disease spreads to his face, just as Lois Lane shows up at his door…
The story continues in the next issue.