
Step aside Deadpool & Wolverine, the Thunderbolts* is the new king of the MCU hill, as it shattered all expectations when it comes to its box office performance and critical response. It now stands as a refreshing entry in yet another franchise that has been milked dry by the House of Mouse. In short, it was great; everybody loves Thunderbolts* now, as we were all pleasantly surprised by its blend of misfit mercenaries and pop psychology.
However, perhaps the most interesting element of this film is its post-credit scene, which has sparked intense speculation among Marvel fans — something we haven’t heard or seen since the Infinity Saga ended. While some initially thought that the post-credit scene contains just another cameo (and it does), many now believe that the mysterious “space crisis” that has been teased in the scene could be laying the groundwork for some major cosmic storyline featuring yet another universal threat.

Fourteen months after the events of the film, the Thunderbolts, now rebranded as the New Avengers, gather in the former Avengers HQ to discuss Sam Wilson’s rights to the Avengers name and their possible copyright infringement. The discussion is then cut short as the team’s attention is drawn to an impending “space crisis” and an extra-dimensional ship entering the atmosphere. The subsequent satellite feed shows a retro-futuristic rocket with an iconic “4” logo on its hull as it approaches the Earth. This means that Marvel’s first family has made its way to the main Marvel universe, which was bound to happen, as they’re scheduled to appear in the upcoming Avengers: Doomsday.
Admittedly, the scene doesn’t exclusively show the members of the Fantastic Four. But, despite the fact that their sudden arrival isn’t exactly surprising, the circumstances of their arrival are definitely worth considering, especially since these circumstances might be tied to the mysterious “space crisis” the Thunderbolts were alarmed by. Now, there are many reasons why the Fantastic Four arrived in the mainline Marvel universe, ranging from interdimensional exploratory travel to coming to the Avengers for help.

Please note that what follows is purely speculative based on rumors and “leaked” information that hasn’t been confirmed by anyone at Marvel or Disney. As such, please take the following information with some skepticism.
The leaked plot for the upcoming Fantastic Four: First Steps points towards the latter, with the Fantastic Four being on the run from Galactus. In their own movie, the Fantastic Four live in this ’60s retro-futuristic universe where they’re celebrated and adored as heroes and protectors after they’ve defeated Mole Man. Sue is pregnant with Franklin, and the team is mostly busy doing space exploration for the government. That is, until Shalla-Bal, the lover of Norin Rad (the original Silver Surfer) and this universe’s Silver Surfer, warns them about the arrival of Galactus.
As one of Marvel’s most formidable villains, Galactus — the planet-devouring cosmic entity — represents a danger that can’t simply be defeated or killed. He’s also connected to Franklin, Reed, and Sue’s son, and the two share a multifaceted relationship in the comics as either foes or allies, depending on the storyline. Purportedly, the arrival of Galactus poses a moral dilemma for the Fantastic Four: either stay and fight Galactus, a cosmic entity that’s seeking to devour their world and is possibly after Franklin, or leave this world in search of another and live to fight another day.

Whatever the case may be, we do see Galactus coming down to Earth, suggesting that he might be searching for something on the planet, and the Earth’s destruction in the latest trailer for the upcoming Fantastic Four, leading up to the events depicted in the Thunderbolts* post-credits scene. Now, whether or not Galactus is the real “space crisis” mentioned in the scene, and whether or not he follows the Fantastic Four through the space-time rift they used to come to the main Marvel universe, remains to be seen once the movie finally drops on July 25, 2025.
It’s entirely possible that he is the threat, as both the Fantastic Four and X-Men have fought against the villain in the comics, and both superhero groups essentially already made their appearances in the MCU. Galactus is also a part of the Secret Wars storyline, which is currently being adapted into Avengers: Secret Wars — where the real space crisis occurs as it centers around the catastrophic collision of different universes.

Galactus then teams up with Doctor Doom, portrayed by RDJ in the upcoming Avengers: Doomsday, and a slew of other villains (Kang, Ultron, Molecule Man, etc.) to take down the Avengers, the Fantastic Four, and the X-Men. But, as previously mentioned, this information is based on rumors and leaked information and is, thus, purely speculative. Please take it with a healthy dose of skepticism and a grain of salt as a preventative measure for a potential disappointment down the line.