‘The Fantastic Four: First Steps’ ending and post-credit scenes explained: how does it set up ‘Avengers: Doomsday’ and more big Marvel questions answered

Full spoilers follow for The Fantastic Four: First Steps.

With First Steps being the precursor to that pair, fans began to question whether Doom would appear in this Phase 6 flick. However, director Matt Shakman consistently denied that would be the case. Indeed, he said it wasn’t part of his purview and later told me that he never considered installing Doom as First Steps‘ primary villain.

An image of Robert Downey Jr reading Jeremy Renner's autobiography while sitting in front of his Avengers: Doomsday trailer — Downey Jr is expected to have top billing as Doctor Doom in Doomsday and Secret Wars (Image credit: Robert Downey Jr’s Instagram)

Ahead of First Steps‘ release, though, Shakman’s tone has changed. Speaking to ComicBook.com, he confirmed that Joe and Anthony Russo, who are directing the next two Avengers films, shot First Steps‘ mid-credits scene. The siblings also filmed Thunderbolts* post-credits stinger, which has big ties to The Fantastic Four’s latest big-screen adventure and Doomsday.

So, is Downey Jr playing Doom in First Steps‘ mid-credits scene? That’s unclear. We only see Doom from the back, and his hood is raised, so I can’t say for sure if it’s Downey Jr. The A-lister isn’t credited with an appearance in the film’s end credits crawl, either. For someone so synonymous with the MCU, you’d expect Downey Jr’s name to pop up if he actually shows up in First Steps.

That said, considering the Russos shot this sequence, I’m more inclined to believe Downey Jr is playing Doom in this scene. First Steps underwent some minor reshoots and pickups around the time that principal photography began on Doomsday. It’s plausible, then, that the Russos filmed this scene prior to commencing work on Avengers 5, which would make it more likely that Downey Jr appears (albeit uncredited) in this footage.

Is there a post-credits scene in The Fantastic Four: First Steps?

Four superheroes in a 1990s animated TV show — First Steps’ post-credits scene shows the main title sequence of The Fantastic Four’s in-universe cartoon (not pictured above) (Image credit: Marvel)

Yes, but truth be told, it’s a nothing burger (from an MCU impact, anyway) of a post-credits scene.

Indeed, the main title sequence to The Fantastic Four cartoon series, which exists in-universe, is this movie’s post-credits scene. It’s a fun little sequence to include, and it’s nice to see those who created it recognized for their work. As I said, though, it doesn’t drop any hints about the future of Marvel’s cinematic juggernaut, so it’s ultimately not worth sticking around for.

How does The Fantastic Four: First Steps set up Avengers: Doomsday?

The Avengers: Doomsday logo imposed on an image of 27 actor chairs with Robert Downey Jr standing off to the right side

Avengers: Doomsday will be released in cinemas worldwide in December 2026 (Image credit: Marvel Studios)

Potentially big spoilers follow for Avengers: Doomsday. Proceed at your own risk.

Given what we learn in First Steps and Thunderbolts* post-credits scene – read my Thunderbolts* ending explained piece for more on the latter – some puzzle pieces appear to be falling into place.

For one, we now know Franklin has superpowers. If we believe what Galactus said about Franklin, i.e., he’s a being of unlimited power, he’ll be one of the most powerful beings to ever exist. Franklin is immensely powerful in Marvel Comics, so that checks out.

Thanks to Earth-828’s various news agencies, it’ll be public knowledge that Franklin possesses superhuman abilities, too. Rumors might also spread about what powers he has and/or how he resurrected Sue – well, if the general public finds out that he did. If they do, Doom will become aware of Franklin’s powerset.

Furthermore, if you believe online speculation about Doomsday‘s plot – read my Avengers: Doomsday hub for more information on its confirmed details – Doom may actually try to prevent the Multiverse’s collapse (via those pesky events known as Incursions) by merging all known universes into a single reality. That’s the basis of Marvel’s two ‘Secret Wars’ comic book runs, which the Russo brothers told me they’re taking inspiration from for Avengers 5 and its follow-up.

A screenshot of a Marvel comic's double page spread showing Franklin Richards using his powers — Franklin Richards could hold the key to creating Battleworld, the planet created out of fragments from various universes (Image credit: Marvel Comics)

If that’s Doom’s aim in Marvel’s cinematic franchise, he’ll need someone like Franklin to achieve his goal. In Marvel literature, Franklin has the ability to warp reality, manipulate matter, and create pocket dimensions. All of those powers would come in handy for an egotistical individual like Doom, who’d view himself as the savior of the multiverse and, as he does in 2015’s ‘Secret Wars’ comic book storyline, install himself as God Emperor of the MCU’s take on Battleworld.

Okay, how does this tie into First Steps‘ mid-credits scene and Thunderbolts* post-credits stinger?

The former makes it clear that Doom has found Franklin. The fact that he has means he’ll have some grasp of the unlimited power Franklin possesses. Franklin’s mom won’t be pleased (to put it lightly!) that another supervillain has come calling to kidnap her child, either.

My best guess, then, is that The Fantastic Four will collectively fight off Doom and, using the Excelsior and Reed’s likely upgraded teleportation device, flee to another universe not unlike their own – i.e., the MCU. That’s why we see the Excelsior emerging from a wormhole in the final Thunderbolts* end credits stinger.

Ghost, Yelena, Red Guardian, and John Walker looking shocked at something happening off-camera in Marvel's Thunderbolts movie — The Thunderbolts – or, rather, The New Avengers – spotted the Excelsior entering Earth-616’s orbit in their film’s post-credits scene (Image credit: Marvel Studios)

Of course, that doesn’t mean they’re safe. The MCU’s take on Earth’s Mightiest Heroes will want to know why a group of superpowered beings has suddenly shown up from another reality. They’re used to extraterrestrial threats emerging out of the blue, and if they don’t get an answer they like, you can bet a fight will ensue between the MCU’s Avengers and The Fantastic Four.

Considering Doom’s own genius-level intellect, plus the plan of action he’s put in place, it won’t be long until he tracks down The Fantastic Four to Earth-616. Franklin may be temporarily safe from Doom’s clutches, but it won’t stay that way.

Whether I’m proved correct or not, I’m convinced Franklin – and Loki, who currently sits at the center of the multiverse in an attempt to hold it all together – is central to Doomsday‘s story. Don’t be surprised, then, if he becomes the human McGuffin that Avengers 5 revolves around and is the individual who contributes most to the soft reboot that Marvel President Kevin Feige confirmed to be coming post-Secret Wars.