Challengers of the Unknown is a comic about a series of four interchangeable men, all armed with their own separate hair color, who all come together to take risks because they survived a plane crash and came to believe they're all living on borrowed time. This leads to the most interesting and distinctive element of the series, that frankly makes it impossible to dislike: they have such an entertainingly matter-of-fact attitude to their own deaths, and a fate-tempting recklessness, that they come off as a little insane. The Challengers are adrenaline junkies that specialize in suicide missions, gleefully playing Russian Roulette with God.
Unlike other comics, this one has an anxious edge that borders on horror. Anyone with superpowers is a villain, and they use their powers in frightening ways. The stories have a background of subtle dread that really speaks my language.
The comic's first two issues are among the best comics I've read from that period - head and shoulders above most of the comics of the time. But by the third issue, you can pick out a formula that starts to emerge. The Challengers basically experience the same story over and over: like Scooby-Doo they split up, they find some weird unexplained phenomenon, usually a monster of some kind, and then, while being blackmailed into doing the bidding of a villain who wants an object that will give him superpowers, they experience four different stories where they experience four different monsters or locales. At the end, the villain acquires powers, and the Challengers trick him in some way where he loses those abilities. In the archetypal Challs story, there are usually "four magic jars" (or something to that effect) that we're left wondering what's in them. (SPOILER: Usually a monster, or maybe an evil mirror.)
This is a very basic example of how to tell a story. "Hey, it's a box. What's inside?"
As soon as the formula clicks in, Challengers becomes unreadable, because there's never a new kind of story, only plugging different numbers into the formula above. The scripter/plotter job on Challengers has to be the easiest gig in the entire world: it's less an act of creation and more like filling out a big Mad Lib. I guess that's the real reason that few people "challenge the unknown" much. Because it's the same thing over and over.
Worse, none of the four characters really have personalities of their own. They are absolutely and totally interchangeable. At least with Doc Savage's aides they had separate skills: Monk was a chemist, Ham was a lawyer, etc. But even that bare bones, primitive level of one-dimensional characterization is absent: the only place one knows that Red Ryan was a circus daredevil was the title page. He never showed any acrobatic ability. When did Rocky, "champion wrestler," ever wrestle anything? You'd think Professor Haley would have scientific skills that he uses, but he's generally no smarter than any of the others.
This is why I find it hard to believe that Challengers is in any way an antecedent to Fantastic Four. Anyone that says that doesn't understand what actually makes FF great: how interesting and distinctive the four lead characters were.
After the descent into a repetitive formula, Challengers isn't readable. I've often been told by people that like traditional Westerns that I "need to acquire an appreciation for formula." Personally, I think the sole function of formula is to prepare you to accept more formula, the same way that the only function of bad movies or books is to prepare you to accept more bad movies or books.
That said, Challengers starts off really, really strong, with two great stories - the second of which, the Ultivac story, has in my opinion, the best art of Jack Kirby's career. Ultivac is a giant robot capable of reading minds. But in a twist, he's actually a sympathetic creature that is trying to protect his own existence. The real enemy is revealed to be the greed of people that want to exploit a human robot for their own purposes.
To quote the Garbage Pail Kids movie: "Ugliness? Meanness of spirit and greed, these are real ugliness. To be blessed with...unusual features...is an adventure."
It's actually pretty shocking, because for the most part, traditional adventure comics of the 1950s are suspicious and distrustful of outsiders of any kind, who are usually malevolent instead of sympathetic. Take for instance the LSH hero Lightning Lord: the only singleton on a planet of twins, if he was in an Andre Norton sf novel (which always feature disabled outsiders as the main characters), or in the outsider-sympathetic Marvel comics, he would be a hero and protagonist instead of a villain. Being an outsider and standing out made him, in the 1950s, twisted instead of likeable.
One of the great additions the Ultivac story was that of June Robbins. Here's an interesting historical footnote about the story: computer operation and programming in the beginning decades was a mostly female, "pink collar" profession, like secretary work. In fact, I like to tell people as a joke that my Grandmother was a computer - and by computer I mean the original definition, a woman with good math skills that double-checks the calculations of engineers. Many of the major figures in the early days of Computer Science are female, like Grace Hopper. It's often hard to believe today, where Computer Science majors are 90% male (I am not making this statistic up, by the way, though this should be obvious to anyone that has ever been around a computer science or IT department - maybe they should stick Twilight posters on the walls of the classes or something).
In fact, I'm getting my masters in Information Science, which includes the technical aspects of information organization work...metadata, electronic database management, etc. I've often heard an extremely sexist (but funny) comment that this line of work is just library science for men. I've also heard of Masters IS students referred to as "guybrarians."
The first Challenger story was likewise really strong, and it forms the Challenger formula: they find a magical box, which they open each section, each of which contains some bizarre creature from the elder world. One really effective scene has them draw straws - and the winners are thrilled when it's their turn. And Kirby deserves credit for creating monsters and menaces that are really fearsome. The strength of the first Challenger story is based on individual images: things like a giant hand that emerges from the sea and crushes a ship underneath.
Like Roger Zelazny, who only wrote two books that I really like yet I count myself a fan of his because of how great those two are (Lord of Light and Amber), I can consider myself a Challengers fan despite the fact that they have an astonishing ratio of bad stories to good ones.
Here's my advice if you find Challengers of the Unknown in Showcase form: check it out from the library, read the first four stories, and give the book back the next day.