After the events of the last ten years, it’s safe to safe that the X-Men are not what they used to be. After Nightcrawler’s death, the schism, the war with the Avengers, all had adverse effects on the mutant team. After the death of Charles Xavier however, the mutants were fractured worse than ever. None felt this pain more so than Beast who couldn’t stand what they had become. Cyclops was a fugitive, Angel didn’t even know who he was, Jean was dead, and Iceman... well, he was pretty much the same, but that’s Bobby for you. Charles’s death was the final straw for Hank McCoy, his faith in the X-Men’s mission broken. But then, as he was always does, Hank got an idea.
Looking at his old graduation photo, Beast remembered back to when this all began, and decided to go back in time (you know this won’t end well), to bring the original five X-Men to the present day so he could show them what their future held. The All-New X-Men (as they would come to be known) would stick around for a bit, Hank wanting to show Cyclops and the others what they had been once, and what they could be again.
This plan (which by the way really didn’t help the whole timeline shattering situation at the end of Age of Ultron), eventually lead to an encounter with Cyclops’s team, where young Cyclops nearly dies, almost erasing the older Scott Summers from existence. Kitty Pryde, who had taken on the responsibility of training the teenage mutants, brought them back to the X-Mansion, where the X-Men began to debate what to do about them. In the middle of that discussion however, another team of time travelling mutants from the future arrive, declaring themselves the X-Men from the future!
This group, featuring an older Kitty Pryde, old Beast, Deadpool, the supposed grandson of Charles Xavier, Molly Haze of the Runaways, Xorn and an Ice Hulk (weirdness, I know), declared that the original X-Men arriving in the present set’s off a series of events that destroy mutant kind. Rachel Grey arrives on the scene, demanding to know who Xorn really is. Taking off her helmet, Xorn is revealed to be Jean Grey, the future self of the time-displaced Jean Grey.
Faced with these facts, Wolverine and the X-Men decide that the All-New X-Men have to return to their own time whether they like it or not. This brings them at odds with Kitty, who wants the time-displaced teens to make their own decisions like she was allowed to when she first joined the X-Men. The group secretly tries to send them back anyway, but find that Beast’s time machine no longer works. While the older X-Men investigate, the time-displaced team runs off, seeking help from Cyclops’s renegade team. However, the other X-Men follow, resulted in a series of fights, leading the young Jean Grey and Cyclops to slip away. Both Wolverine’s and Cyclops’s X-Teams decide to work together to find them (Cyclops and Logan coming close to killing each other... dudes need to hug it out).
Magick however, has grown suspicious of the future X-Men, and uses her powers to go through time to the future to find out the truth, taking young Iceman and Beast with her. There, she discovers the REAL future X-Men, including her brother Colossus and older versions of Iceman and Jubilee. There, she learns in the future, Beast and company form the new Brotherhood of Mutants, intent on going back to the past to ensure mutant dominance, and that sending the All New X-Men back to the past was the first step.
Armed with this new knowledge, Magick heads back and tells the rest of the X-Men the truth. The New Brotherhood strikes, but accompanying Magick is the X-Men of the future, and soon an all out war erupts between the two sides. For a brief and glorious moment, Cyclops and Wolverine put aside their differences, and lead the X-Men in a massive charge against the Brotherhood, defeating them though at the cost of the future Colossus’s life. Both enemies and friends are sent back to the future in the aftermath, the crisis over.
However, the ramifications of this battle were heavy. Kitty Pryde, angry that Wolverine, Iceman and Storm, the three people she loves most, went behind her back with the decision to try sending the All-New X-Men back to the past, decides that if they can’t trust her to make the decisions concerning the five young mutants then she doesn’t belong at the school anymore. In a shocking move, she joins Cyclop’s X-Men, taking the students with her!
Battle of the Atom was Bendis’s first big X-Men crossover, which he and the other writers knocked out of the park. Drawing on the mutants past, present, and possible futures, Bendis weaved a story that changed the landscape of the X-Men once again, while at the time showing us what they were capable of when they stood together. Might not see it often since Schism, but when it does happen, it is a wonder to behold.