Bryan Singer manages to redeem the X-Men franchise from the depths of irrelevance.

X-Men fans, this is the movie that you've been waiting for as the casts of both the old-school and new-school film lineups are now officially back on the big screen. All of them.

Warning: Possible Spoilers Ahead!

Based on the Marvel Comics comic book The Uncanny X-Men, the storyline in this film alternates between the retro past and a dystopian future, wherein mutant-hunting robots called the 'sentinels' have completely taken over.

These seemingly indestructible machines are designed to hunt down both mutants and their human allies, incarcerating them in internment camps to be disposed off later (which means Magneto was right about something for once). The remaining X-Men members are pretty helpless against them, and their survival depends mostly on evading capture.

This is all later revealed to have originated from a particular event in 1973 involving Mystique (Jennifer Lawrence) and the creator of these robots, Dr. Bolivar Trask (Peter Dinklage). The only chance left for both mutants and mankind is to somehow change history, a task which now rests in Wolverine's claws (Hugh Jackman).

That's right, the most stubborn of all X-Men must somehow convince rivals Charles Xavier (James McAvoy) and Erik Lehnsherr (Michael Fassbender) to put aside their differences and work together for the greater good.

Bryan Singer, the visionary director who brought us the original X-Men movies, says Days of Future Past will take viewers on an emotional ride.

You have young Professor X struggling with his inner-demons while trying to come to terms with what happened in 2011's X-Men: First Class...

The vengeful Mystique who is determined to put a stop to Trask's diabolical genocide plans...

And the callous Magneto who seems even more determined to ensure that the future never happens, even if it means doing the unthinkable... killing off one of his own.

Surprisingly, all this drama makes the Wolverine come across as the most emotionally stable and clear-headed character throughout the entire film. If anything, this further proves that even superheroes have to struggle with doubts and insecurities.

But what really tugged at our heartstrings would have be the brutal fight scenes between the mutants and sentinels. We'll spare you all the gory details, but just know that it would be impossible not to grimace while watching our heroes being viciously cut down one by one.

Thankfully, there are some lighthearted and endearing moments to give you a break from all the dreariness. One particular scene we really liked involves super-speedy mutant Quicksilver (Evan Peters) causing a big ruckus in the White House.

We admit that at times it was a bit of a struggle to keep up with the interspersed scenes, overlapping storylines and cameos. But if this was final X-Men film that we'll see in this lifetime, we certainly weren't disappointed.

X-Men: Days of Future Past opens in theaters 22 May 2014. Be sure to stick around after the credits for an extra special scene that is a prelude to "X-Men: Apocalypse".