Supervillain team-ups had been rare in the DC Golden Age. Batman had two that I'm aware of; in Batman #2, The Joker Meets the Catwoman was published. However, it was not really a team-up as such, just a story with two different villains. Then, in Batman #25, came Knights of Knavery, featuring the Joker and the Penguin. This was a real supervillain team-up; oddly it was not repeated. Superman #77 had a story featuring Luthor, the Toyman and the Prankster, and of course there were several supervillain team-up stories in All-Star Comics tales of the Justice Society of America. The famed Flash of Two Worlds (published exactly one year before FF #6) had featured the talents of the Fiddler, the Shade, and the Thinker.
So team-ups were not unheard of, but they were uncommon. Of course, Marvel changed all that. As the story begins, the FF is reading their fan mail. Reed discovers that a young fan is recuperating in a hospital nearby, and stretches over to meet him. This gives Stan the opportunity to explain how Mr Fantastic's uniform elongates with him (some mumbo-jumbo about unstable molecules).
The fan mail segment also features the first mention of the Yancy Street Gang, a long-running gag in the series. As you can see, they specialized in tormenting the Thing:
This gives Ben the opportunity to muse that he longs for a villain worthy of his great strength, like Dr Doom or the Sub-Mariner. And speaking of that duo, Dr Doom is, at the same time, encountering Subby:
Doom is determined to goad the Sub-Mariner into resuming his campaign against the surface world:
We also learn that the Sub-Mariner is still sweet on Sue, and that his feelings for her are returned:
But almost at that moment, Namor enters their quarters, having flown through an open window. We know from an earlier scene that Namor is carrying a device that Dr Doom will be able to use to pull virtually anything on Earth to him, and that anything in this case is the entire Baxter Building:
But this is a double-cross on the Sub-Mariner, too, as we learn here:
Dr Doom tugs them out into space, apparently intending to suffocate them. The FF put on a bunch of fishbowls (although there are no apparent oxygen tanks attached to them), as does Subby. The Torch is unable to fly, and Mr Fantastic finds that the cold of space reduces his stretching power. Ben's strength and Sue's invisibility are useless. So what can be done?
Well, not to spoil the drama, but the Sub-Mariner swims around in a pool of water for a bit, then makes a leap through a meteor shower to Doom's ship. Doom tries to electrocute him, but:
In his haste to escape, Doom hitches a ride on a passing meteor, to his (apparent) death in the vastness of space. The Sub-Mariner returns the Baxter Building to its original position. Namor flies off in Doom's craft, leaving the FF in something of an awkward position:
Comments: Something of an offbeat story; the FF only survives because one of the "villains" prevents the other villain from winning. This became a common theme in the Marvel team-ups.
