Marvel's Avengers: Doomsday is coming, what do we know so far?

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

In the past few years, the franchise has experienced a run of lukewarm reviews and sporadic success, and a messy split with an actor who'd held a key role.

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

Avengers: Doomsday, where he'll make his full debut, will show whether the superhero universe can still attract more casual cinemagoers alongside devout fans.

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

Robert Downey Jr.

He was "the one person who could play" the role, according to bosses when they introduced him on stage at San Diego's Comic Con in 2024.

The reveal sparked ear-splitting 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 signature character's trilogy alone making more than $2.4bn (£1.7bn) around the world.

But critics saw re-casting him as a different character as a sign of those in charge running low on ideas.

As for who's joining Downey Jr in Doomsday, it's almost easier to name an A-lister who isn't involved, such is the vast length of its call sheet.

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 Doomsday teasers drop, momentum and speculation build for the MCU's next big thing, due to land in cinemas on Friday 18 December, with a sequel scheduled for the following year.

So what do we know so far?

Warning: The following contains what anyone who isn't up to date with the MCU might consider to be spoilers.

Such is the hype around Doomsday's teasers, their "will return" endings have become a meme.

First came confirmation that Chris Evans' Steve Rogers "will return".

After first suiting up in 2011's Captain America: The First Avenger, Evans' "Cap" became a lynchpin within the MCU's biggest box office successes.

But the self-proclaimed possessor of "America's ass" has spent more time sitting on it since Avengers: End Game than saving the world.

We saw Steve slow-dance with his beloved Peggy Carter at the end of the 2019 blockbuster, having travelled back to the mid-1900s.

A later flash-forward showed him elderly, symbolically handing 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 Earth's other mightiest heroes in the present day?

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

Talking of offspring, Doctor Doom sure seemed interested in Reed Richards (Mister Fantastic) and Sue Storm's son Franklin in a brief but ominous scene at the end of 2025's Fantastic Four: First Steps.

Might Doom's plan involve this growing group of ultimate nepo babies?

Let's hope he's not nearby if Steve needs a babysitter when his career break's over.

The parenting problems are piling up.

Next, it's Thor's turn, with Doomsday's second teaser showing him tearfully praying to his father to help him protect his adopted child.

Here, our catch-up with Thor starts with the Asgardian God on what looks like a much-needed mental health walk.

He's seemingly afraid of a threat against Love, who's been by his side since their 2022 film Love and Thunder.

As he prays, he pleads for the strength of the "All-Fathers" so that he "may fight once more".

Thor's taken numerous hammer blows in the past.

His beloved Jane Foster passed through the pearly gates of Valhalla into the afterlife, while his sibling Loki veers wildly from being an ally to an adversary.

Oh, brother.

Thor's literally on his knees and Doom's only just getting started.

It's been a long time coming.

Starting in 2000, the original X-Men film series had varied success across 13 entries.

Overall, they were a powerful force, totalling billions of box office dollars with a cast stacked with big names.

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

Bosses waited to unleash their mutants, but now the shackles are off as the latest teaser confirms they're entering the MCU.

The X-Mansion could do with a clean, couldn't it?

But the full force of energy bursting from Cyclops' visor should obliterate those cobwebs.

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

At best, the characters' relationship is complicated.

At its toxic worst, it's explosive.

Here, they share weary smiles and philosophical thoughts on death and legacy.

History tells us Magneto's intrusive thoughts often win, so who would he side with if Doom came calling?

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

Having cherry-picked fan favourites, Doomsday looks set to ignite the MCU's big plans for X-Men.

Fake Doomsday teasers and talk of leaks are rife online.

So are fan theories that a fourth "will return" is coming, with some predicting we'll return to Black Panther's homeland Wakanda.

Super Bowl ad breaks are ideal for dropping trailers, so is Doomsday building towards a touchdown on Sunday 8 February?

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

Tom Holland is back as Peter Parker and swinging into cinemas on Friday 31 July, before Doomsday looms towards screens on December.

A follow-up, Secret Wars, is scheduled for December 2027.

It's a while since the MCU's box office and critical success peaked, but Fantastic Four: First Steps helped it find its feet again when it made more than $500 million (£372m) worldwide.

And if Marvel's bringing Spider-Man and Robert Downey Jr in villain mode to the battle, it could soon find itself marching back to the top of the box office.