The Fantastic Four: First Steps repeatedly confirmed the existence of Latveria, but stopped short of revealing whether Marvel's First Family has ever encountered Doctor Doom.
In the movie's mid-credits scene—which was filmed on the set of Avengers: Doomsday by the Russo Brothers—we were taken five years into the future, with Doctor Doom teleporting into the Baxter Building. Kneeling in front of the young Franklin Richards, the villain had his mask in one hand and seemed to be gently touching the boy's arm with the other after lifting Franklin's hand to, presumably, his scarred face.
It left us with more questions than answers, and won't be fully explained until it's put into context by Avengers: Doomsday next December. However, we may have some additional insights today, courtesy of scooper @MyTimeToShineH.
According to the insider, Franklin reminds Doom "of his own son." While it's safe to say that Victor Von Doom is there to take Franklin—his powers to create new realities promise to be key in the villain's plan to rule the Multiverse—this goes a long way in explaining why the stinger was as touching as it is sinister.
We can only theorise about what this means for Avengers: Doomsday, but it's still pretty weird that Doom is showing his horribly scarred face to a little boy. However, as Franklin isn't fazed, what if Doom is here looking for the Fantastic Four's help? And what if the mask is only ceremonial and his face isn't scarred at this stage?
If the Earth-828 Variant of the character rules over Latveria with his wife and son by his side, that may be why he's treating Franklin with such care. However, if a fight with the Fantastic Four follows, along with the destruction of this reality in an Incursion event, then we can theorise that this is the moment Doom gets his scars and, ultimately, the very different costume and mask we've seen in promo art.
Something along those lines playing out also gives Doom a reason to hate Reed Richards, as their relationship in the MCU hasn't been touched on at all as of yet.
While this rumour clears up a few of our biggest questions coming out of The Fantastic Four: First Steps, it's clear that there's still an awful lot we don't know as Avengers: Doomsday approaches.
Earlier this year, filmmaker Matt Shakman was asked about why his movie didn't connect to Thunderbolts*'s Fantastic Four tease. "[That] end credit scene was also created, you know, relatively late in my process too, so that was not something that I was familiar with because it hadn’t been created at the time that I was working on my script, you know?"
He added, "I often use the metaphor of it’s, you know, like a relay race, right? You pass the baton, you run your section of it as hard and fast as you can, do the best you can with your version of Fantastic Four – Earth 828, this world – and then you pass the baton, in this case to the Russo brothers."
Avengers: Doomsday officially stars Chris Hemsworth, Anthony Mackie, Winston Duke, Tom Hiddleston, Sebastian Stan, Letitia Wright, Paul Rudd, and Robert Downey Jr. Wyatt Russell, Simu Liu, Tenoch Huerta Mejia, Florence Pugh, Danny Ramirez, David Harbour, Hannah John-Kamen, and Lewis Pullman all make their Avengers franchise debuts in the movie.
The Fantastic Four: First Steps leads Pedro Pascal, Vanessa Kirby, Ebon Moss-Bachrach, and Joseph Quinn join them, as do X-Men franchise stars Kelsey Grammer, Patrick Stewart, Ian McKellen, Alan Cumming, Rebecca Romijn, James Marsden, with Deadpool & Wolverine star Channing Tatum.
Avengers: Doomsday is set to be released on December 18, 2026, with Avengers: Secret Wars scheduled to arrive on December 17, 2027.