The end of the world is approaching. What do we know so far?

After 37 films, the Marvel Cinematic Universe (MCU) needed an antidote to “superhero fatigue.”

In recent years, the franchise has experienced a series of mixed reviews and sporadic success, as well as a complicated breakup with an actor who had played a key role.

After testing potential cures, bosses scoured the MCU’s vast source material and summoned the villainous Doctor Victor von Doom as the center of its future.

Avengers: Doomsday, where it will make its full debut, will show whether the superhero universe can still attract more casual moviegoers alongside fervent fans.

But who has enough star power to lift a series that has racked up a total box office of more than $30 billion (£26 billion) worldwide?

Robert Downey Jr.

He was “the only person who could play” the role, according to bosses when they introduced him on stage at San Diego Comic Con in 2024.

The revelation sparked heartbreaking celebrations from the audience in the room.

Having played Iron Man Tony Stark in 10 films, Downey Jr is a guaranteed draw for many, with his iconic character’s trilogy alone making over $2.4 billion (£1.7 billion) across the world.

But critics saw his recasting as a different character as a sign that those responsible were running out of ideas.

As for who is joining Downey Jr in Doomsday, it’s almost easier to name a star who isn’t involved, such is the length of his call list.

Chris Evans, Chris Hemsworth, Pedro Pascal, Tom Holland.

Florence Pugh, Hayley Atwell, Letitia Wright, Vanessa Kirby.

(Excuse us while we take a deep breath.)

Sir Patrick Stewart, Sir Ian McKellen, Benedict Cumberbatch, Channing Tatum.

You get the idea.

As the Doomsday teasers drop, momentum and speculation build for the MCU’s next big thing, set to arrive in theaters on Friday, December 18, with a sequel planned for the following year.

So what do we know so far?

Warning: The following contains what anyone not up to date with the MCU might consider spoilers.

Such is the hype around Doomsday teasers that their “will return” endings have become a meme.

First came confirmation that Chris Evans’ Steve Rogers would “return.”

After first starring in 2011’s Captain America: The First Avenger, Evans’ “Cap” became a keystone of the MCU’s biggest box office hits.

But the self-proclaimed owner of “America’s ass” has spent more time sitting on it since Avengers: End Game than saving the world.

We saw Steve slow-dancing with his beloved Peggy Carter at the end of the 2019 blockbuster, after traveling to the mid-1900s.

A later flash-forward showed him aged, symbolically handing over his iconic shield to his former wingman – literally, a winged man – Sam Wilson.

But in the new Doomsday teaser, Steve looks in his prime, so will Doomsday reunite his younger self with the other mightiest heroes on modern-day Earth?

There is also a brief glimpse of him holding a child who, we are led to assume, is his baby.

Speaking of offspring, Doctor Doom certainly seemed interested in Reed Richards (Mister Fantastic) and Sue Storm’s son Franklin in a brief but disturbing scene at the end of Fantastic Four: First Steps to 2025.

Could Doom’s plan involve this growing group of ultimate nepo babies?

Hopefully he won’t be around if Steve needs a babysitter once his career break is over.

Parental problems pile up.

Next, it’s Thor’s turn, with Doomsday’s second teaser showing him in tears praying to his father for help in protecting his adopted child.

Here, our catch-up with Thor begins with the Asgardian God in what feels like a much-needed sanity walk.

He’s apparently afraid of a threat to Love, who has been by his side since their 2022 film Love and Thunder.

As he prays, he pleads for the strength of the “Fathers of All” so that he “can fight once more.”

Thor has taken many hammer blows in the past.

His beloved Jane Foster has passed through the pearly gates of Valhalla into the afterlife, while his brother Loki goes wildly from ally to adversary.

Oh, my brother.

Thor is literally on his knees and Doom is just getting started.

This has been a long time coming.

Beginning in 2000, the original X-Men film series enjoyed varied success over 13 entries.

Overall, they were a powerful force, grossing billions of dollars at the box office with a cast full of big names.

Disney’s deal to buy 20th Century Fox in 2017 included the film rights to the X-Men characters, uniting them with the Marvel collection it already had under its watch.

The bosses have been waiting to unleash their mutants, but now the chains are off as the latest teaser confirms that they are entering the MCU.

The X-Mansion could use a cleaning, right?

But the full force of the energy bursting from Cyclops’ visor should clear those cobwebs.

Professor X and Magneto, played by Sir Patrick Stewart and Sir Ian McKellen respectively, are back.

The relationship between the characters is complicated at best.

At worst toxic, it’s explosive.

Here they share weary smiles and philosophical reflections on death and legacy.

History tells us that Magneto’s intrusive thoughts often get the better of him, so who would he side with if Doom called him?

Nightcrawler, played by Alan Cumming, and Mystique, played by Rebecca Romijn, will also return, while Hugh Jackman proved that Wolverine is still a cut above in his blockbuster 2024 collaboration with Deadpool.

Having picked out fan favorites, Doomsday looks set to spark the MCU’s big plans for X-Men.

Fake Doomsday teasers and discussions about leaks are commonplace online.

So are fan theories that a fourth “Come Back” is coming, with some predicting we’ll return to Black Panther’s homeland of Wakanda.

Super Bowl commercial breaks are great for launching trailers, so is Doomsday gearing up for a touchdown on Sunday, February 8?

Spider-Man: Brand New Day is perhaps even more likely to have its moment during one of the most-watched events in the world.

Tom Holland returns as Peter Parker and hits cinemas on Friday July 31, before Doomsday hits screens in December.

A sequel, Secret Wars, is planned for December 2027.

It’s been a while since the MCU’s box office and critical success peaked, but Fantastic Four: First Steps helped it find its feet again, earning over $500 million (£372 million) worldwide.

And if Marvel brings Spider-Man and Robert Downey Jr in villain mode into battle, it could soon find itself at the top of the box office.

Listen to Newsbeat live at 12.45pm and 5.45pm weekdays – or listen again here.