Issue(s): Fantastic Four #41, Fantastic Four #42, Fantastic Four #43
Published Date: Aug-Oct 65
Title: "The brutal betrayal of Ben Grimm!" / "To save you, why must I kill you?" / "Lo! There shall be an ending!"
Credits:
Stan Lee - Writer
Jack Kirby - Penciler
Vincent Colletta - Inker

Review/plot:
The return of the Frightful Four, the only group that has beaten the Fantastic Four. Medusa has become very dominant, pushing around the other members and just generally being belligerent. She's also showing herself to be very powerful - despite the oddness of her power it is never played for laughs.

Poor Paste Pot Pete, on the other hand, can't get the other members of his team to call him the Trapster, even with the convincing argument that "The name Trapster sounds much more important!". Also, Medusa, who was leading Pete on the last time we saw them, is now making time with the Sandman.

Ben Grimm, having sacrificed his humanity to defeat Dr. Doom last issue, quits the FF and winds up near the Frightful Four. The Wizard snags him and brainwashes him with the Id Machine. "Evil" Thing is identifiable because he chain smokes his ceegars, even during fights.

When the rest of the FF show up to try to bring Ben home, they are attacked, defeated, and captured, mainly by the Thing alone, demonstrating his power level relative to the other members of the team(s).

Reed and Johnny manage to free themselves, but Sue, trapped only in a plastic bag, needs to be rescued.

On the other hand, in the subsequent fight, she is shown to be using dual forcefields at once, which is a nice display of her increasing power level.

Nonetheless the FF are defeated again, and this time Johnny is subjected to the Id Machine as well.

The Invisible Girl gets to do some rescuing and it winds up being Reed and Sue vs. all of the Frightful Four plus the Thing and the Human Torch.

Fantastic Four #43 was not reprinted in the Marvel's Greatest Comics series due to the fact that it had been recently reprinted in Fantastic Four annual #9. I originally didn't have that, and i guessed that the FF won by appealing to the love and friendship of their hypnotized members, and then rally to defeat the Frightful Four. In fact, it turns out that the Human Torch was only faking his conversion, allowing Reed and Sue to escape with a captured Thing.

Reed performs delicate brain surgery on the Thing. Meanwhile, Sue can't stop yapping in his ear.

In the rematch fight, the Thing briefly wakes up from his post-surgery sleep, crushes the Wizard's power suit, and then falls back asleep.

It's enough to get the rest of the Frightful Four totally demoralized. Medusa escapes, aided by the fact that Johnny is attracted to her (as pointed out by Reed!). The other members just... fold. Ok, the Wizard's suit is crushed and Mr. Fantastic snags "Trapster's" glue gun...

...but what's up with the Sandman's sudden lack of fight?

With the Frightful Four so cowed, the only problem for the Fantastic Four is getting the police to believe that they've got some super-criminals that need picking up.

No wonder Reed eventually builds a prison in the Negative Zone!

When the Thing wakes up for real, he and Reed mend fences, and then the poor guy falls back to sleep dreaming that one day he can get married.

Medusa continues to be pretty bad ass in this arc.

Another cool factor is a brief look in on Dr. Doom, angry about his hands getting damaged in his recent battle with the Thing.

Despite their sudden surrender at the end, this arc does a lot to keep the Frightful Four as an A-list villain team. The Wizard's Id Machine also works as a cheap but useful way to highlight some of the underlying tension between the Fantastic Four. Overall, a fun set of issues.

Quality Rating: C+

Historical Significance Rating: 2 - first Id Machine

Chronological Placement Considerations: Issue #40 ends with the Thing quitting the FF and issue #41 picks up in the same scene.

References:

• Dr. Doom's hands were damaged in Fantastic Four #40.
  
• As soon as Doom's hands are healed, he plans to use his "emotion changer ray". A footnote tells us that this will occur in the upcoming Fantastic Four annual #3.

Cross-over: N/A

Continuity Implant? N

Reprinted In: Marvel's Greatest Comics #32, Fantastic Four annual #9

Too bad this is the height of the Frightful Four's prowess. They won't be A List for long. Their appearances to date have been outstanding, but once Medusa defects, the evil FF just begins declining in quality. Even with the future addition of Thundra, the team just isn't the same. I like Thundra as a character, but I think the femme fatale aspects of Medusa was an important part to the chemistry of the team. After Thundra, they can't even keep a fourth member - much less an intriguing one.

Don McGregor has a letter in #42.

more "Reed Richards is a megalomaniac villain":

examining the unconscious Thing after Reed's attempt to un-brainwash him, Reed exclaims, "There's still a chance that I've won!".
won - odd choice of word if his real intent was to help the Thing.

also, a few panels back, Reed's got the most awesome mad scientist face as he's got the Thing strapped to his machine.

I agree with Chris. Once Madam Medusa left the evil FF, they began to decline in quality. Medusa seemed so sadistic and confident when she was a member of the Frightful Four that she made the perfect female foe!