WARNING: The following contains spoilers for Amazing Spider-Man #34, by Nick Spencer, Patrick Gleason, Matthew Wilson, DeeCunniffe, Chris O'Halloran and VC's Joe Caramagna, on sale now.

Alternate futures are a dime a dozen in the Marvel Universe. Heroes and villains are always traveling through time, forwards and backwards and sideways, trying to stop some kind of terrible future from happening, or to get a better one going. Decades ago, things got so out of hand that Marvel started numbering all of its possible futures to try and keep track of things.

Throughout the years and through timelines like the Days of Futures Past, the Ages of Ultron, and the world of Cosmic Ghost Rider, one question has always remained: Which of these futures is the real future of the Marvel Universe?

For many fans, the guessing was part of the fun, and for the characters and comics themselves, the mutability was part of the draw. The future could always be changed. Nothing was set in stone, and what a hero did today could have an almost unknowable impact on tomorrow.

Or, at least, that was what we all thought, right up until this week’s Amazing Spider-Man #34 made the shocking revelation the the world of Marvel 2099 was Marvel's official future.

RELATED: Spider-Man 2099 Might Have Literally Run Out of Time

The issue begins with Miguel O’Hara, the Spider-Man from the of 2099, stumbling through present-day New York City, looking for Peter Parker. Something bad is happening to his reality, and his future’s scientists have traced the event’s origins to the current day Marvel Universe.

When Miguel finds the present-day Spider-Man, in the midst of trying to halt an invasion of Doombots, Peter barely blinks. Time-travelers are that common, and, as Miguel points out, he’s not even the first alternate future web-slinger that Parker’s met. But then Spider-Man 2099 explains something to Spider-Man 2019 that changes everything we knew about Marvel's future.

“Our scientists ... discovered an anomaly – something that was causing all this. It led them back here ... Just like it always does,” O’Hara says.

He continues, explaining that all of the other Spider-People and alternate realities that have appeared over the years are “fixed within an infinite multiverse. They are other Earths.” But the 2099 future, the one everyone thought was simply one of many possible futures, is, in fact, the same Earth as Earth-616.

Present-day Spidey explains it as “a super-position” – both realities are fixed in time, there is no branching. And that, O’Hara explains, is the problem. His reality is collapsing because Earth-616’s future is always changing, as the other heroes of Marvel's future are trying to deal with in Marvel 2099 event.

RELATED: Marvel's 2099 Event Foreshadows the Arrival of a Thunder

Spider-Man 2099 future

Created in the early '90s, Marvel's 2099 was a fan-favorite publishing line that took place about 100 years in a hi-tech future controlled by corporations. With most of Marvel's modern heroes lost to time, a new generation of heroes like Miguel rose up in a world filled with shocking developments like a time-tossed Doctor Doom taking over the United States.

What this means for the Marvel Universe going forward is, as of now, unclear. Miguel O’Hara disappears before he can explain anything else to Peter Parker, who now finds himself transported to 2099, where he's facing down an army of Doombots.

That said, the ramifications could be huge. If it is, in fact, true that the 2099 universe is the only future for Marvel’s Earth-616, then what does that mean for all the other alternate futures out there? Does Old Man Logan’s dark fate carry the same weight if we know it’s not the “real” future?

Perhaps more importantly, does that mean that present-day Peter Parker – or Doctor Strange or whoever – can pull a Back to the Future II and find out exactly what’s going to happen? Perhaps fittingly, only time will tell.

KEEP READING: Into the Spider-Verse 2: How Does Oscar Isaac's Spider-Man 2099 Fit In?