You know, I think you can argue that Edmond Hamilton had too many good ideas and didn't always spread them out as much as he should have.
I would hold "Captain Future and the Seven Space Stones" (Winter 1941) up as evidence of this. The 5th Captain Future adventure is crammed to overflowing with wonderfully imaginative ideas, but there simply isn't time within this relatively short novel to properly develop all those ideas.
The plot here is different in one important way from the previous four Captain Future adventures. Previously, the identity of the main villain was unknown, with there being a number of suspects to choose from. This time, we know who the bad guy is right from the start--Doctor Ul Quorn, a Martian/Venusian/Human hybrid who once went to prison for performing horrible experiments.
Now he's free and trying to acquire the Seven Space Stones, relics of an ancient Martian scientist and the key to a mysterious super-weapon.
The mystery here is two-fold: What can Ul Quorn do with the Space Stones if he acquires them all and why does he seem to already have a grudge against Curt Newton (aka Captain Future) and the Futuremen?
This premise leads into a competing treasure hunt, with Ul Quorn and Captain Future each trying to get the Space Stones before the other does. It's a race that takes them from Earth to Venus to Mars to an outlaw asteroid called the Pleasure Planet.
Within this story, Hamilton really does cram in one cool idea after another. For instance:
1. Ul Quorn is traveling with an interplanetary circus, using his scientific skill to put on a magic act. His minions (aside from a mind-numbingly beautiful Martian femme fatale) are genetically-engineered members of the circus freak show whose skills come in handy when its time to steal a Space Stone. For instance, one guy has enlarged cup-like ears that give him super-hearing, while another has a chameleon ability to change his skin color and blend in with the surroundings.
2. Captain Future at one point encounters a space hermit who despises technology and lives on a remote asteroid.
3. Another asteroid, the Pleasure Planet, is outside planetary police jurisdiction because the crook who owns it slapped some huge rockets on it and stopped its orbit, thereby using a legal technicality to become a world outside the law.
4. The effects of the super-weapon and the final fight this leads to are cool and awesome and absolutely epic--but I can't tell you about it in detail without spoiling the surprise for anyone who hasn't read it.
5. Since the Futuremen have no evidence against Ul Quorn at first, they go undercover at the circus in various disguises. Grag the robot's disguise and the personality he assumes is hilarious.
6. Ezra Gurney, the aging Space Marshall who is one of Curt's regular allies, has a legitimately touching encounter with an aging space pirate he had tried to catch years before.
7. There's a cult of Martians who are determined to bring back the scientific glories of their planet that were lost 2000 centuries ago.
8. Did I mention that there's a mind-numbingly beautiful Martian femme fatale?
All this makes "Captain Future and the Seven Space Stones" the most fun of the first five books in the series. But, ironically, it also borders on being unsatisfying. The above ideas simply aren't fleshed out as much has they might have been.
For instance, several of Ul Quorn's "freaks" assist him, but several others are simply introduced, described well enough to wet our interest, then left unused. The coolest of them is probably the Moon Wolf, a six-legged wolf from Io who had a human brain transplanted into it, giving it intelligence and the power of speech. You simply do not introduce us to a six-legged talking wolf from Io and then not do anything with him! I was expecting a fight between the Futuremen and the freaks, but we never get to see this.
The Hermit, the femme fatale, Ezra's former space pirate nemesis, the Martian cultists--all these are interesting characters. All are underused.
Other plot points come and go too quickly. At one point, Captain Future and Planetary Police agent Joan Randall are undercover in the gambling dens on Pleasure Planet. The normally straight-laced Joan is posing as a spoiled rich girl, which is a fun idea. But we get only one line of dialogue from her while playing this role, then the story moves on to other things.
There are two more important items to bring up. Ul Quorn is taken alive at the end--I think he's the first major villain in any of the stories to be taken alive. This is because his back-story and his scientific genius are setting him up to become Captain Future's re-occurring arch-enemy. I have no complaints about this. The hybrid mad scientist is a great villain.
Also, Otho the Android gets a pet. This is a "meteor mimic"--a small animal that can shape-change--which Otho names Oog. Remember that Grag the robot had a metal-eating "moon pup" named Eek. Remember also that Grag and Otho are always arguing--mirroring Ham and Monk from the Doc Savage novels. Giving both a pet further mirrors Ham and Monk, who had an ape and a pig respectively that they employed to annoy each other. That Hamilton (perhaps under editorial order) was deliberately lifting this dynamic from Lester Dent's Doc Savage tales becomes even more apparent when Oog is tossed into the mix. I'm a bit conflicted about this. As much as I love Hamilton's work as a writer, I would have preferred to see the Futuremen develop their own unique personalities. On the other hand, Oog and Eek are pretty cool.
But "The Seven Space Stones" is still a great story. Reading this one leaves you very aware of just how well-qualified Edmond Hamilton was to eventually switch to writing comic books and produce so many great Legion of Superheroes and Superman tales. That same sense of pure fun and internally consistent logic is there. Heck, Captain Future and his men would have fit into DC's Silver Age universe perfectly.
There are 15 more Captain Future novels and 5 short stories, so there's a good chance we'll talk about him again in the future. But that's it for Captain Future as a part of the "In Order" series. We still have two Perry Mason movies to go and we'll also get back to Jongor of Lost Land for his last two stories. After that--well, as of this writing (about two months before it posts) I haven't decided yet.