I learned that black magic does exist, but there are terrible forces beyond those that men know, and those who dare tamper with them suffer terrible consequences! 
Challengers of the Unknown #72 is an issue of the series Challengers of the Unknown (Volume 1) with a cover date of March, 1970.
Synopsis for "A Plague of Darkness"
At Murlin Chemicals in Manhattan, the owner stays behind after hours to perfect his alchemical immortality serum. The mixture is off and he dashes it to the ground in anger, where a black cat comes to lap it up. The cat wanders outside and an old woman pets him; she immediately turns white as a ghost and begins attacking bystanders, running and cackling in the streets.
At a hospital across town, Red is released from surgery and his vision is back to normal but Prof remains in critical condition. A pale madman bursts into the hospital, shoving and punching strangers and barges into Prof's room, attempting to throw him out the window. The Challs subdue the deranged man and a doctor enters to explain how there are over a dozen similar patients who are all catatonic and unresponsive to treatment but who occasionally burst into violent fits. Corinna Stark thinks their condition is similar to an old alchemy text that she once read but before the team can investigate, reporter Alfie Eisen eavesdrops and says that he has to tell the public. Ace pleads with him to give them some time before breaking the story or else it will cause a panic. Eisen agrees to hold it until midnight.
Red and Rocky hit the streets to investigate while Ace and Corinna go back to her apartment to dig into her library. Murlin is also wandering in alleyways, poisoning vagrants and turning them into zombies. He narrowly escapes detection from Rocky while he and Red fight off a zombie. Meanwhile, Corinna discovers that the zombie-like infection can be passed by touch only if you have the same blood type but once it reaches someone with Type O, that person can spread to anyone. As she explains it, a news reporter becomes rigid and pale in a swarm of zombies. Ace rushes out to get his car while Corinna devises an antidote.
As the four heroes reconvene, Murlin attempts to dig into the municipal water supply and poison all of New York City. Rocky leads them back to Murlin Chemicals, where the villain sprays them with a fine mist that disguises him as a young woman. Corinna is unaffected and convinces them that they were just speaking to a dangerous old man immediately before Ace calls in a complete lockdown that could cripple the city and kill several vulnerable residents to save the world. They rush back into Murlin Chemicals, where Red and Rocky are exposed to the zombie concoction. Ace and Corinna knock out Murlin and she gives her antidote to her teammates, curing them. The antidote gets distributed in time to stop an outbreak and Ace thanks Corinna for saving the world.
Appearing in "A Plague of Darkness"
Featured Characters:
Supporting Characters:
- Dan (Phone call only)
Antagonists:
- Mr. Murlin (First appearance)
Other Characters:
- Alfie Eisen (First appearance)
- Ken (First appearance)
Locations:
- Manhattan
- Murlin Chemicals (First appearance)
- Murlin Chemicals (First appearance)
Synopsis for "Nobody Lives Forever… or Do They?"
Gambler Al Denton has run out of luck in Las Vegas, losing all his money. On his flight back home, the plane's fuselage explodes, sending him hurtling back to earth. Before he reaches the ground, Fate scoops him up in his mammoth hands and explains that he is the one billionth human whom he has guided to the threshold of death, so his life will be spared and he is given the chance to make one wish for how his life will go. He desires immortality and it is granted. He uses his inability to be harmed to become a criminal and ends up killing a guard at a bank vault. When he is captured, he is sentenced to life in prison, where he sits, aging and trapped until past the year 4000.
Appearing in "Nobody Lives Forever… or Do They?"
Featured Characters:
- Al Denton (First appearance)
Other Characters:
- Fate (First appearance)
Notes
- The credits for the second story are revealed in “Let’s Chat with the Challs” from Challengers of the Unknown #77.
See Also
- Cover gallery for the Challengers of the Unknown series
- Images from Challengers of the Unknown Vol 1 72