AMAZING SPIDER-MAN (1963) #377, [Fine/VF (7.0)]

After their tenacious battle last issue, Cardiac determines that Styx has to be eliminated! So to that end Dr. Elias Wirtham tricks Stone into bringing Styx to a New Jersey medical facility for treatment. But Cardiac's scheduled tests will put Styx out of action... permanently! Wow, so much for the Hippocratic Oath! Fortunately though, a well-placed spider-tracer leads the web-slinger directly to Cardiac's location! And the Amazing Spider-Man clashes with Cardiac to save Styx and Stone! Talk about an ethical dilemma! Origin of Styx and Stone.