Challengers of the Unknown #72

Challengers of the Unknown #72 (On Sale: December 2, 1969) has a cover by Neal Adams.

The Challengers of the Unknown star in "A Plague of Darkness" by Denny O'Neil, Dick Dillin and Frank Giacoia. While in the hospital waiting for Red to be released, the Challs learn of a deadly plague, which is turning people into zombie-like creatures. We know that he plague is the work of a chemist named Murlin, who was trying to find an elixir of youth. The plague is spread first by a cat, which is what the cover alludes to.

While most of the Challs are tracking down Murlin, Corinna finds a cure in an old alchemy book. Murlin is going to put the elixir i the city water supply and is able to trick the Challs into leaving him alone, but Corinna sees through his illusion and in the end is the one who stops Murlin. They then use the city's waster system to spread the antidote.

The back-up story is "Nobody Lives Forever... or Do They?" by Dave Wood and Lee Elias. This is not a Challengers story, but rather some mystery book filler.

Edited by Murray Boltinoff.