Avengers: Endgame's script explains how Tony Stark/Iron Man (Robert Downey Jr.) knew they needed to travel back to the '70s for another shot at the Tesseract/Space Stone. Following their defeat in Avengers: Infinity War, Earth's Mightiest Heroes were given the chance to bring back everyone who got dusted by Thanos' (Josh Brolin) snap five years prior. Thanks to the idea of Time Heist suggested by Scott Lang/Ant-Man (Paul Rudd), the remaining team went back in time to collect all six Infinity Stones prior to the Mad Titan getting his hands on them. That resulted in a fun way to revisit various points in the universe's history including the Battle of New York in The Avengers.

Tony, alongside Scott, Steve Rogers/Captain America (Chris Evans) and Smart Hulk/Bruce Banner (Mark Ruffalo) were tasked to return to 2012 in the hopes of getting Mind Stone, Space Stone, and Time Stone (which was still with The Ancient One at that time). But while Bruce was able to cajole the Sorcerer Supreme to hand him out the Eye of Agamotto, and Steve retrieved Loki's (Tom Hiddleston) scepter, Tony and Scott lost the Tesseract due to unforeseen events. Having only one shot at time traveling with limited Pym Particles, Tony improvised and convinced Captain America that they could still get their hands on the Space Stone - they just had to travel further back in time.

Related: Phew, It’s Good That Avengers: Endgame Cut Iron Man’s Soulworld Scene

The pair was transported to the '70s at Camp Leigh where lo and behold, the Tesseract also was, as well as some more Pym Particles, allowing Tony and Steve to travel back to their primary time setting. Avengers: Endgame, however, didn't explain how Tony knew that both the Space stone and Pym Particles were at the same place at that particular point in time. There have been various theories trying to explain this, but now, we finally get the answer thanks to the full Endgame script now available online. After Tony figured out time travel in his cabin, there's scene description on page 33 of the Avengers: Endgame script that reads: “PHOTOS crowd a side table: Pepper, Morgan, Tony. Even one of HOWARD STARK, PEGGY CARTER & HANK PYM UNDER A SHIELD SYMBOL.”

Tony talks to Steve in Avengers Endgame

This wasn’t in the film as the sequence quickly picked up with Pepper (Gwyneth Paltrow) reading a book on composting while Tony came in after he put Morgan to bed. Since we didn't see the image described, it's possible that it was taken at an entirely different time - after all, they all worked together until Hank Pym (Michael Douglas) resigned from the organization in 1989 as seen in the cold open of Ant-Man. However, the fact that there was supposed to be an emphasis on the photo, not to mention that all of them turned out to be in Camp Leigh during the visit, was a clear set-up for Tony's eventual idea to go back to the '70s.

It's unclear why that particular shot was cut from Avengers: Endgame (if it was filmed at all). Since it was already running a bit long at over three hours, it's understandable that the Russos were keen on making the film as succinct as possible, and perhaps it just so happened that the aforementioned scene was ultimately edited out from the final cut. That being said, considering that it was supposed to be a set-up to one of the best sequences in the movie, perhaps it would've been for the best if they kept it in. If anything, it's safe to say that fans won't be complaining if the film was a few seconds longer.

More: Um, How Long Did Captain America Live After Avengers: Endgame?

Key Release Dates