Most superheroes in the Marvel Universe possess alter egos, but not all these other identities are heroic. Marvel enthusiasts are likely familiar with the Dark Phoenix, Jean Grey’s sinister alter ego in the X-Men. However, there’s another Marvel heroine with a dark side that hasn’t been portrayed on the big screen. The Fantastic Four have a storied history, one brimming with secrets and revelations, and 40 years ago, Marvel’s first family acquired an unexpected — and unwelcome — new member.

A fateful encounter with an android called the Hate-Monger led to Sue Storm, also known as the Invisible Woman, developing an alternate personality named Malice. Sue’s battle with her villainous alter ego has some parallels to the Dark Phoenix saga, although Malice’s role in the Marvel Comics universe is considerably smaller than that of Jean Grey and the Phoenix Force.

While the Phoenix was ultimately revealed to be a separate entity that commandeered Jean’s appearance and persona, Malice is a distinct personality residing within Sue Storm’s subconscious. When this personality surfaces, it spells trouble for everyone nearby, as Malice can wield Sue’s immense powers without her compassion and empathy. Malice has previously attacked Sue’s family, prompting Sue to take significant measures to shield her loved ones from her darker side. Based on available information about “Fantastic Four: First Steps,” the introduction of Malice to the Marvel Cinematic Universe, if it occurs, seems distant. Nonetheless, with Sue now in the MCU, her menacing alter ego could be a ticking time bomb ready to detonate.

Malice debuted in 1985, in “Fantastic Four” #280, by John Byrne and Jerry Ordway. In the story, the FF is fighting a mad scientist known as Psycho-Man and his android henchman, Hate-Monger. Psycho-Man built the android specifically to manipulate people into feeling powerfully negative emotions, and Hate-Monger’s abilities piggybacked on that to draw out Sue’s Malice persona. Malice immediately turns on the Fantastic Four and battles the incredibly powerful She-Hulk, who had recently replaced the Thing as a member of the FF. Sue’s husband, Reed Richards (aka Mister Fantastic), is able to figure out how Hate-Monger inverted Sue’s emotions and manages to manipulate Malice’s feelings in order to return Sue’s consciousness to the forefront, defeating her evil persona.

After this, the Fantastic Four defeat Psycho-Man and Hate-Monger, and they probably believe that they’ve seen the last of Malice. Unfortunately, the personality had really just gone dormant within Sue’s subconscious, waiting for the right trigger to bring her back and retake control of Sue’s body. Eventually, while working with the Silver Surfer, Sue finds herself in close proximity to the Soul Stone, and Malice re-emerges, attempting to take control of the Soul Stone for herself.

Sue is able to draw on the Infinity Gem’s power (this is before they were re-dubbed Infinity Stones) to subdue Malice once again, but even then, she isn’t free of her alter ego. During the events of the “Infinity War” crossover event, Sue finds an opportunity to follow a new path forward for herself and Malice.

Malice returns once again during the events of “Infinity War,” when Thanos scans Sue’s mind and inadvertently frees her alter ego. Sue and Malice fight for control of their shared body, but this time around, Sue decides to take a different approach with her villainous half. Sue merges her consciousness with Malice’s, hoping that this will finally let her be free of her alter ego’s evil intentions. Instead, the mind-melding changes Sue’s personality, not unlike what happened when Spider-Man initially joined with the Venom symbiote and tried using it to his advantage only to have the alien being begin to take control of his body.

Sue is eventually saved from Malice by her own son, Franklin. In an alternate timeline, Franklin has grown up to become the superhero known as Psi-Lord. That version of Franklin travels to the primary Marvel timeline, where he uses his powers to force Malice out of his mother’s mind. That doesn’t kill the persona permanently, though, and Sue and Psi-Lord are later forced to combine their powers to trap Malice in the mind of another villain called Dark Raider. The Fantastic Four completely defeat Dark Raider, which presumably means that Malice is gone for good — but then again, no one ever really dies in comic books.