Alone among the major comic book film franchises, the "X-Men" flicks have been able to navigate seven films now without pressing the "reboot" button on any of its major characters. Think of the redundancy of the new Spider-Man films, the cringeworthy Bana-to-Norton-to-Ruffalo saga of the Hulk. Meanwhile, you still have Patrick Stewart as Charles Xavier, Halle Berry as Storm, Ian McKellen as Magneto. Somehow, too, Hugh Jackman has hung around long enough to appear in nearly every one of the movies, including two standalone "Wolverine" titles. They've even pulled the same characters out of time with "X-Men: First Class," exhuming the mutants' backstories from the early '60s and bringing in new faces with old names.
The question becomes, how long can they go without breaking down? The answer comes in the form of "X-Men: Days of Future Past," which is a clunky name for an otherwise outstanding genre movie. It's also, conspicuously, the point at which the franchise opens to any and all possibilities (except for Jackman leaving; at 200-odd-years-old, and impervious to aging, we're stuck with him as Woverine as long as he'll have the part). This is where we fold the old-guard mutants back onto their younger selves, allowing James McAvoy to claim Xavier as his own and, to a greater degree, giving Michael Fassbender the reins of Magneto and Jennifer Lawrence the definitive Mystique.
We open on a gnarly future in which awesomely powerful robots called Sentinels hunt and exterminate mutants, and pretty much anyone else they feel like wiping out or enslaving. They're imbued with the chameleonic DNA of Mystique, allowing them to absorb mutant powers and retort with the same. Some of these fight sequences ... gracious and good golly. They are ferocious and they are high-stakes. Bryan Singer, directing again, has mastered at least part of this comic-book movie thing. Kill a few heroes and everyone perks right up.
Ah, but here's the twist. Kitty Pryde (Ellen Page, Juno-riffically) has the ability to do some kind of mental time-travel thing with Bishop (Omar Sy) and save everyone just in the nick o', but eventually they figure the only way out of this hellhole of a 21st century is to do a proper "Back to the Future" time-swap and have Wolverine go slap some sense into Xavier, Magneto and Mystique back at the dawn of the Sentinel program ... (cue wakka-wakka electric guitar) ... in ... NINETEEN SEVENTY-THREE ... Three ... three ...
Wolverine gets the gang back together before there's even a gang. Ten years after "First Class," Xavier is a veritable junkie on a serum that dulls his psychic powers but keeps his legs functional. Magneto is doing extraordinarily hard time a country mile beneath the Pentagon for his apparent role in whacking JFK. Also, Beast is hanging around. But Mystique is on a rampage and if she puts a bullet into a fellow named Trask, the military contractor behind the Sentinel program (Peter Dinklage, owning a role not written specifically for a little person), then everyone will hate mutants and fund Sentinels and the future will turn out like "Blade Runner" crossed with "The Matrix."
Schlocky time travel, A-minus-list actors, true brutality by the Sentinels, a menacing turn by Fassbender and a general tone of high play make this probably the best film in the series, somewhat of a lesser spark than Christopher Nolan's "Dark Knight" masterpieces but nearly as satisfying. It also contains what might be the single most memorable scene among the "X-Men" installments to date: a whirlwind shoot-'em-out moment that a young Quicksilver (Evan Peters) owns with such casual aplomb, and Singer depicts with such moviemaking joie de vivre, that for an instant the whole venture crystallizes into a moment of Zen. This should be dark fun, emphasis on the dark, emphasis on the fun. "Days of Future Past" balances both.