WARNING: The following contains spoilers for Fantastic Four #30 by Dan Slott, Ze Carlos, Jesus Aburtov, and VC's Joe Caramagna, on sale now

One of the greatest strengths of the Fantastic Four has always been the bond at the heart of the team, uniting them as a family above all else. But because of all that extended time together, the team knows each other better than any of their enemies, which means that they know the perfect ways to try and break each other down.

When half of the group is corrupted by Knull in Fantastic Four #30 during King in Black, the Fantastic Four learn once and for all that the greatest threat to the superhero team is themselves.

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Because the Fantastic Four has spent so long working together as both a superhero team and as a family, the members of the team have a keen awareness of what drives each other and what their weaknesses could be. That's what makes any internal conflict between them so devastating. That's also what makes the Knull-possessed Thing, Human Torch and Valeria Richards such dangerous threats to the rest of the group when they are possessed by the overwhelming influence of Knull. While Sue initially has hope for them, Reed points out how Sue's brother and his best friend are the two people in all the world "who know the best ways to hurt us," setting up defenses to hold them at bay.

Likewise, outside the Forever Gate at the site of the original Baxter Building, Franklin and Bentley are confronted by a corrupted Valeria, who quickly lashes out at the pair but focuses much of her attention against Franklin. Although the uncorrupted members of the group are able to survive the onslaught from their teammates -- and likewise, the corrupted heroes are able to keep up with the strategies and schemes of their heroic teammates -- each of the uncorrupted heroes also tries to get through the personal pains that their loved ones dish out against them. Valeria insults Franklin over the recent loss of his powers, zeroing in on the insecurities that have already been plaguing Franklin since that process began.

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But Franklin is able to take inspiration from these insults, deciding that if he's nothing in the face of threats like Knull, then he has nothing to lose in fighting them. While fighting her, Human Torch insults Sue about her habits of trying to watch after him after the disappearance of their parents, accusing her of trying -- and failing -- to become a mother figure to him. Sue ignores these put-downs, noting that she and her brother have been working on these issues for years. But perhaps the most heartbreaking confrontation comes between Reed and Ben. Corrupted by Knull, Ben reminds Reed of all the things that have happened to his "loved ones" because of the commitment Reed has to explore science and the unknown -- and that he never learns his lesson.

Notably, Ben even brings up a recent revelation from their time fighting the Griever, which revealed that in one possible future, Reed Richards will do something so wrong that Thing will drop any pretense of being friends with him and instead work to beat him to death with his bare hands. Reed, Sue, and Franklin all survive their encounters, and soon their loved ones are restored following the conclusion of the storyline.

While Franklin and Val makeup quickly and Sue quickly returns to her old habits of watching over Johnny, Reed and Ben actually take the time to talk about the confrontation, with both of them admitting that there were kernels of truth to Ben's anger at Reed. But Reed is quick to forgive his best friend, with the pair sharing a drink and reaffirming their bond.

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