*Warning: Avengers: Endgame spoilers ahead*

Avengers: Endgame has broken countless records since its premiere last Friday, April 26, but one detail that surprised fans was the lack of a post-credits scene, which has been a staple of Marvel movies ever since Iron Man teased the existence of the Avengers way back in 2008.

But although the movie didn't offer a traditional post-credits sequence, it did manage to make a subtle nod towards the MCU's past, hinting at where the ever-growing series of films may head in the future.

The video from Insider reveals how the Marvel Cinematic Universe is like a giant mobius strip, the geometric phenomenon Tony Stark uses to solve the puzzle of time travel within the film. The movies leading up to Avengers: Endgame have often been referred to as the Infinity Saga, and a mobius strip resembles an infinity symbol when placed on its side.

Instead of a post-credits scene, the film ends with the sound of Tony Stark striking metal with his hammer to build the very first Iron Man armor, seeming to indicate that the MCU can circle back on itself and re-explore its own past in future movies.

Fans were pleasantly surprised by the hidden meaning inside the credits.

It's all about that time travel!

It's possible this isn't the last we've seen of Marvel's big heroes.

Fans were eager for more from Avengers staples who met their doom in the Endgame.

Twitter's minds were officially blown.

What could one do with time travel technology like this?

Some people thought the trailer might be teasing some very specific things in the MCU's future.

Others felt bringing back old heroes through time sounded too good to be true.

Though nobody is sure what's coming in the future, one thing is certain—Avengers: Endgame is a movie that cannot be missed. If you haven't seen it yet, grab you tickets and get to a theater!

Marvel Studios' Avengers: Endgame | Policy Trailer www.youtube.com