Appearing in "The Enemy Within!"
- Iron Man (Appears on a computer screen, TV, or hologram only)
- Spider-Man (Appears on a computer screen, TV, or hologram only)
- Wolverine (Appears on a computer screen, TV, or hologram only)
- Iron Man doppelganger (Appears on a computer screen, TV, or hologram only)
- Spider-Doppelganger (Appears on a computer screen, TV, or hologram only)
- Wolverine doppelganger (Appears on a computer screen, TV, or hologram only)
- New York City
- Magus' citadel
- Devos' ship
Synopsis for "The Enemy Within!"
The Magus has begun his private war to destroy Earth's super-heroes utilizing twisted doppelgangers as part of his quest to gain power. Knocking the pieces off a chessboard he was playing with his very own doppleganger of Thanos, Magus shows this impostor visuals of his plan already in motion: dopplegangers are already attacking Spider-Man, Iron Man, and Wolverine. The phony Thanos warns his master not to underestimate his foes, but the Magus assures him that he has carefully crafted his plan and nothing could possibly go wrong. He then turns his attentions to the Four Freedoms Plaza headquarters of the Fantastic Four.
There, the Human Torch has stormed into Reed's lab to question the way Reed has been running the team as of late. When Reed tries to brush him off so he can complete his re-working of the Encephalizer to monitor Franklin's mutant powers, Johnny explains that is exactly his point -- that Franklin wouldn't be at risk of his powers flaring out of control had Reed not foolishly explored the Inniverse, and almost cost Franklin his life. When Reed doesn't answer right away, Johnny shoots some fireballs at him to get his attention. Pointing out that it was one of Reed's failed experiments that turned them into the Fantastic Four, and that their lives have been going downhill ever since. As he dodges Johnny's flame blasts, Reed justifies himself by saying that his inquiries serve a definite purpose, that they must pursue these things to determine their threat levels and find some way to protect themselves. As Reed tries to extinguish Johnny's flame, Johnny asks Reed how many dangers has he accidentally unleashed because of his experiments, and melts the extinguisher. By this point their argument has attracted the attention of the Thing, who pretends to be insulted by their leaving him out of the fight. Ben breaks it up by clapping his hands together, the force snuffing out Johnny's flame and splitting them apart. With the fight over, Johnny storms out of the building and Reed refuses to confide in Ben as to what the fight was about.
Leaving his lab, Reed feels bad for shutting Ben out, but he can't help but feel that Johnny's assessment of the situation was correct. He decides to check on his son and finds Sue putting the boy to bed. Sue confesses to her husband that she feels that they have not been acting like responsible adults and Franklin has been suffering as a result, and admits that their son deserves better than what they are providing for him. Reed promises that they will re-evaluate the situation after they have had some rest. As they close Franklin's bedroom door, the boy's eyes open and begin to glow...
Meanwhile in Central Park, Alicia Masters is spending time with her step-father the Puppet Master. She thanks him for providing the Fantastic Four with the information on the Skrulls that led to her rescue. Phillip tells his step-daughter that his love for her exceeds his hatred of the Fantastic Four and so helping them was not a choice. She confesses that she is still struggling to adjust to all the changes that have happened since she was abducted, particularly the news that Ben has been dating another woman named Sharon Ventura. She can't blame Ben for moving on when it seems that she was lost to him forever. The Puppet Master assures his step-daughter to have faith, telling her that things will work out for the best. Secretly thinking to himself, Phillip Masters vows to make them work if they don't do so naturally.
Meanwhile, back at his secret hideout, the Magus begins the next phase of his plan. By pushing a button on his control panel, a doppleganger is dispatched to attack Reed Richards as he is working in his lab at the Four Freedoms Plaza. Unsure who this attacker is, how he managed to breach security, or how he managed to mimic his powers, Mister Fantastic is determined to defeat his foe. His attacker claims to be Reed's dark side, but Reed is not willing to accept that as fact. Mocking Reed for his cold scientific mind, the doppleganger reaches for a rack of weapons on the wall and grabs a rivet gun and fires. Although a number of rivets are shot, Reed redirects them back at his attacker using his elastic body. However when he gets too close to his foe, the doppleganger attacks using his own stretching powers in the most brutal ways possible. First headbutting Reed, then ramming a fist down his throat and then expanding it to try and suffocate his enemy. In order to try and break free, Reed forms his body into a top like shape and begins spinning around as quickly as he can, whipping his foe around the room.
At that moment, Johnny is on campus at Empire State University where his thoughts are focused on taking more responsibility for his life instead of acting like a fool. Lost in thought he does not hear one of the ESU football players trying to pick on him until he shoves Johnny. Losing his temper, Johnny decides to entertain the jock's desire to see his flame powers by pulling him up close and then igniting his head. The footballer is clearly frightened, but before things can escalate any further, Johnny is told off by a female student, who tells Johnny off as his irresponsible use of his powers could have seriously burned the student. With the situation diffused, the woman storms off and Johnny is completely floored by the woman.
As Reed battles on against his double, the Thing has checked in at a gym across town to test out some new weights that have been specially ordered for him. Unfortunately, they are completely totaled when Ben tries them for the first time thanks to the unexpected surprise arrival of Sharon Ventura. Back at the Four Freedoms Plaza, the struggle between Reed and his duplicate continues until the evil Reed manages to reach for a Microwave Pulsator weapon and blasts Reed with it, knocking him out. With his foe defeated, the Mister Fantastic doppleganger begins transforming into a strange tentacled creature and envelopes Reed within itself and they begin to merge. This sets off the Encephalizer, and hearing the alarm, Sue rushes to the lab to see what the commotion is. When she arrives it appears that Reed is fine and there are no signs of his attacker or that there was a battle. Reed tells her everything is fine and that he was just running a test. When Sue tells him that she is still on edge after their battle with Occulus, Reed tells her not to worry about Occulus, telling her that she can trust him. But as Reed hugs his wife, his evil smile and glowing red eyes seem to contradict this.
Meanwhile in deep space, the escape ship of Devos is recovered by a Skrull shuttle. Devos is looking forward to killing more Skrulls. On board the ship he is covered by Paibok the Power Skrull who is surprised to hear the rumors of Devos' existence are true. When Paibok learns how Devos also had a run in and was defeated by the Fantastic Four, the Skrull puts away his weapon and suggests that they work together to destroy their mutual foes, as he is heading to Earth to destroy them. When Devos asks how Paibok intends to destroy the Fantastic Four, the Skrull shows him his greatest weapon: Lyja, the Human Torch's wife, alive and well and recovering in a regeneration tank.
- This story is part of the Infinity War event and events in this story expands on events that occur in Infinity War #1. The scenes where Wolverine, Spider-Man, and Iron Man are battling their dopplegangers are expanded upon in Infinity War #1, and portions of Reed's battle with his double are covered in that same story.
- Reed and Ben were last seen in Sleepwalker #16 while Johnny and Sue were last seen in Sleepwalker #14.
- The Magus and his Thanos Doppleganger appear here simultaneously with events occurring in Infinity War #1.
- The Encephalizer machine in this story has the brain patterns of the team that Reed took in Fantastic Four #357 and is a larger version of the device he first used in Fantastic Four #363 to track Sue and Franklin.
- Reed mentions that the device is supposed to monitor the psychic barriers dampening Franklin's mutant powers. Franklin purposely cut off his powers in Fantastic Four #245. Reed has been concerned that those barriers were weakened by Occulus when he kidnapped the boy in Fantastic Four #362–365.
- Johnny's refers to how the Fantastic Four was created thanks to one of Reed's experiments going wrong. This of course is a reference to the accident in Fantastic Four #1 that gave the group their powers.
- Franklin appears here following the events of the 2nd and 3rd stories featured in Fantastic Four Annual #25.
- The Puppet Master was last seen in Fantastic Four #356–358 where he helped expose Lyja as a spy for the Skrulls and provided information to the Fantastic Four to rescue the real Alicia from space.
- Mention is made to the fact that Ben has been dating Sharon Ventura. During the period when Lyja was posing as Alicia Masters (starting in Fantastic Four #265 as explained in Fantastic Four #358) she eventually married the Human Torch in Fantastic Four #300. Believing that he lost Alicia for good, Ben started pursuing a relationship with Sharon since inviting her to join the team in Fantastic Four #307. Ultimately, Sharon was mutated into a She-Thing in Fantastic Four #310 leading to their relationship forming in Fantastic Four #317. After Sharon was cured by Dr. Doom in Fantastic Four #350 she disappeared shortly thereafter following the events of Fantastic Four #354. She resurfaced last issue, and as revealed in Fantastic Four #375 she is spying on the Fantastic Four for Dr. Doom.
- Following her appearance here, Alicia next appears in Marc Spector: Moon Knight #41.
- The woman who berates Johnny here is identified as Bridgette O'Neil in Fantastic Four #371.
- Reed is possessed by his Doppleganger for the duration of the Infinity War saga until he is freed in Fantastic Four #370.
- Paibok and Lyja were last seen seemingly perishing in Fantastic Four #358, how they survived the destruction of the Skrull War World is revealed in a flashback in Fantastic Four #390. Devos was last seen after he was defeated by the Fantastic Four in Fantastic Four #359.