Sebastian Stan Revealing ‘Avengers 4’ Spoiler Resurfaces with New Meaning

Captain America star Sebastian Stan really did let slip an Avengers 4 detail when he confirmed some major Marvel players would have their Avengers: Infinity War deaths reversed.

Speaking at ACE Comic Con in April, Stan confirmed he filmed a major scene for an Avengers movie and "everybody was there," including Nick Fury (Samuel L. Jackson), Hank Pym (Michael Douglas) and Janet van Dyne (Michelle Pfeiffer).

Ant-Man and the Wasp, released in July, revealed Hank and Janet were victims of Thanos' (Josh Brolin) snap that wiped out half of all life in the universe, including daughter Hope (Evangeline Lilly) — leaving Scott Lang (Paul Rudd) trapped in the Quantum Realm.

Stan downplayed the slip with an assist from Infinity War co-stars Anthony Mackie and Winston Duke, telling ET just before release, "I don't think I revealed anything crazy. Like, everyone's gonna be in this movie."

"Nobody crazy, that I mentioned, would not be in this film," Stan added. "Michael Douglas could come in and pour a tea for one scene, for all you know."

When Mackie asked if Douglas is in the movie, Stan confirmed he was.

"He is in the movie. At least the movie I was in," he said. "It might not be in this movie, but it might be in the other one."

Because Pym didn't appear in Infinity War and was later dusted in Ant-Man and the Wasp, fans on Reddit pointed out Stan accidentally confirmed expectations Pym and the other dusted characters would be resurrected in Avengers 4.

Douglas has since remarked the Ant-Man sequel is directly connected to the Infinity War followup, telling On Air with Ryan Seacrest the Quantum Realm is "the key" to Avengers 4 and beyond.

"The Quantum Realm plays an important part in all the next chapters, I think, of the Marvel films," Douglas said.

"There are things that you see back there that [Ant-Man and the Wasp director] Peyton [Reed] has put in there," Marvel Studios chief Kevin Feige divulged during an Ant-Man and the Wasp press conference in July. "Where and how they pay off in the near term and the long term remains to be seen."

Evidence of a journey into the Quantum Realm surfaced in October when a merchandise leak reached the internet, showing Thor (Chris Hemsworth), Rocket Raccoon (voice of Bradley Cooper) and Captain America (Chris Evans) suited up in what appear to be the same Quantum Realm exploratory gear worn by Pym when the scientist ventured into the mysterious dimension in search of his long-missing wife in Ant-Man and the Wasp.

Avengers 4 opens May 3.