This article contains spoilers for The Amazing Spider-Man #55, by Nick Spencer and Patrick Gleason.
Marvel just retconned Spider-Man's most controversial story. In 2007, Marvel shocked Spider-Man readers by rewriting their canon and continuity. Spider-Man struck a literal deal with the devil, Mephisto, in order to save the life of his beloved Aunt May. It came at a terrible price, with Mephisto erasing Peter Parker's marriage to Mary Jane Watson out of history.
In truth, Marvel had been trying to find a way to write the marriage of Mary Jane and Peter Parker out of continuity for years. The decision had been made in 1987, and the comic book publisher swiftly learned the truth of the old adage "act in haste, repent at leisure." Writers swiftly began to feel they had changed the character of Spider-Man a little too much, making him difficult for new readers to relate to. This had led to countless ill-conceived attempts to break Peter and MJ up, with Marvel even trying to kill Mary Jane off in a plane crash at one point. But "One More Day," by J. Michael Straczynski and Joe Quesada, was frankly the most insane idea of all. Unfortunately, it stuck.
Most Spider-Man books since 2007 have attempted to ignore "One More Day," but current Amazing Spider-Man writer Nick Spencer has taken a very different approach. His new villain Kindred is clearly the Harry Osborn of the pre-OMD timeline resurrected from Hell and seeking vengeance on Spider-Man. And Amazing Spider-Man #55 has just retconned the deal Spider-Man struck with Mephisto in "One More Day," revealing Mary Jane has already remembered the original timeline. Kindred is unleashing his wrath on Spider-Man (again) when MJ stays his hand. "He doesn't remember," she tells him. "You see that, don't you? As angry as [Peter] is... he would say anything right now to save all of us."
Curiously enough, this is actually something of a re-retcon. As discussed by CBR's Comic Book Legends Revealed, one scene in "One More Day" did indeed see MJ whisper something to Mephisto - and letterer Chris Eliopoulos looped the text "You will make me remember everything" in the speech bubble so it was barely legible. A later special, Amazing Spider-Man: One Moment In Time, revealed MJ had actually said something very different - but clearly, that has now been rewritten in turn. It's something of an amusing twist.
This retcon is a dramatic one, though, because it essentially rewrites every Spider-Man story told since 2007. Take, for example, one story shortly after MJ returned to New York in Amazing Spider-Man #606, when footage of Spider-Man making out with Black Cat wound up hitting the news; that scene feels almost as though it was orchestrated by Mephisto to taunt her. Years later, she wound up working for Tony Stark, an arc that again reads very differently given she remembered her past interactions with Iron Man while she and her husband lived in Avengers Tower. It's impossible to overestimate the sheer scale of Nick Spencer's retcon.
Amazing Spider-Man #55 comes to a dramatic conclusion, and it's difficult to predict where things are going to go next. One thing is for sure, though; when the dust settles from his confrontation with Kindred, Peter will want to know the truth from Mary Jane. The relationship between Spider-Man and Mary Jane Watson may never be the same again.