Ever since Marvel relaunched their line of comics under the Marvel Now banner, a majority of the company's biggest titles have been focused on time travel.
In the first issue, a distraught Beast brings the original X-Men – including the teenage version of himself – to the present in order to rattle his former teammate Cyclops, who recently killed their mentor Charles Xavier while possessed by the Phoenix.
But in the current Battle of the Atom crossover, the young X-Men have been demanded to return to their era.
And the X-Men of the future have come back in time to make sure this happens.
At the end of the Age of Ultron mini-series, also by Bendis, the space-time continuum is revealed to be broken due to years of time travel shenanigans in the Marvel Universe.
Over in Guardians of the Galaxy, also by Bendis, a cabal of intergalactic leaders are concerned about earth's heroes constantly meddling with the space/time continuum without regard for how that impacts the rest of the universe.
In an interview with Comic Book Resources last year, Bendis hinted at a crossover between All-New X-Men and Guardians of the Galaxy that would deal with the ramifications of the X-Men's time travel through the universe.
The obstacles and adversaries the cast of "All-New X-Men" will confront come from around the globe and the farthest reaches of space. "The original X-Men coming to the present day will have consequences, and this goes back to something I mentioned in our 'Guardians of the Galaxy' interview. It's my feeling that every one of these space-time continuum abuse acts has a butterfly effect. Sometimes it happens directly to the abusers, and sometimes that effect happen across the galaxy. I may not feel like there's some immediate fallout right here on Earth, but somewhere, something is happening. You know how 'the butterfly flaps its wings and there's a hurricane in Africa?' The Marvel version of that is the original X-Men travel time and have an adventure. Then, across the galaxy, something happens. We're going to discover what that is in both 'All-New X-Men' and 'Guardians of the Galaxy.'"