Superhero movies tend to come in one of two flavors nowadays: dark and broody, or light and upbeat. X-Men: Days of Future Past has it both ways, and it does both exceedingly well.
The movie plays fast and loose with its source material, and with time-travel logic in general. Days of Future Past is based on a fan-favorite 1981 story arc of the same name, from back in the day when you didn't have to shell out a cool $40 a week just to follow one storyline. It also marks the return of director Bryan Singer, who hasn't helmed an X-Men flick since 2003's X2.
The action starts in a grim and violent future (it was 2013 in the comics, so the filmmakers have tacked on an extra decade) that sees robotic Sentinels scouring the earth to kill anyone carrying the mutant gene. With the superhero holocaust nearly complete, the few surviving X-Men, led by Professor X (Patrick Stewart) and Magneto (Ian McKellan), have holed up in a Chinese monastery to stage a last-ditch effort to prevent the apocalypse: Kitty Pryde (Ellen Page) will use her powers to send Wolverine (Hugh Jackman)—or at least his consciousness—five decades into the past, where he's to track down the scientist who designed and built the murderous Sentinels. Wolverine's job isn't to kill Dr. Bolivar Trask (Peter Dinklage), though, but to save his life—and to retcon the hell out of the X-Men cinematic universe.
Once Wolvie wakes up in his super-buff, if disturbingly veiny, 1973 body, Days of Future Past makes an enormous and seamless tonal shift. Singer and his cadre of screenwriters have a blast with the period trappings—before he can save the world, Wolverine must defeat a waterbed and other pop-culture touchstones of the '70s. The film offers wry nods to everything from lava lamps to the iconic uniforms of Pan Am flight attendants as Logan sets out to round up the old crew. See, in order to stop the assassination of Trask by the blue-skinned, morally conflicted mutant known as Mystique (an underused Jennifer Lawrence), Wolverine has to track down the younger versions of Charles Xavier/Professor X and Erik Lehnsherr/Magneto, played by James McAvoy and Michael Fassbender respectively, and convince them to put aside their differences.
It's even harder and weirder than it sounds. Charles has lost his mutant powers, along with his faith in humans and mutants alike, and Erik is doing hard time beneath the Pentagon for supposedly killing JFK.
If none of that makes any kind of sense, don't worry—Singer and company do an admirable job of doling out the massive amounts of exposition required to recap six movies (four under the X-Men banner and a pair of Wolverine solo outings). In fact, part of Days' charm is how deftly it manages to meld all those disparate elements into something that feels cohesive enough to work as a series installment, but self-contained enough to stand on its own and serve as a jumping-on point for newcomers.
It also corrects one of the missteps of Matthew Vaughn's otherwise sturdy 2011 installment. While X-Men: First Class relied entirely on the strengths of characters who had been established in the first three movies, Days gives fledgling mutants their due. The most notable addition to the cast is Evan Peters, who pretty much walks off with the movie as Quicksilver, a mutant with super-speed and sticky fingers. Peters only has a couple of scenes, but they're doozies. One of them—a deconstructed fight scene that slows down the action in order to walk us, step by mischievous step, though Quicksilver's supersonic world—is unquestionably the highlight of the film. It might just be the highlight of the spring movie season altogether.
It's a moment that illustrates Singer's greatest strength as a director: his ability to home in on compelling characters, even in the midst of a genre that can easily rely on pre-branding and spectacular FX.
It's telling that Quicksilver's fantastic moment in the spotlight is also the closest Days comes to a stand-out set piece. Sure, there's some wholesale destruction during the deftly edited climax that spans 50 years and two storylines, but the movie mostly eschews visual scale for narrative ambition. It's the most emotionally affecting X-Men outing so far, and sets the franchise up remarkably well for 2016's X-Men: Apocalypse. A few of the last-minute plot machinations will be puzzling to newcomers, but they'll engender a lot of goodwill among fans. If there was something you particularly hated about Brett Ratner's poorly received 2006 installment, Days of Future Past probably fixes it.