Avengers: Endgame had its share of memorable moments, but one sequence in particular will go down as one of the most iconic and enduring scenes in MCU history.

During the climactic battle, Thanos manages to defeat Thor, Iron Man, and Captain America - but Steve Rogers isn't about to stay down. As the Sentinel of Liberty dusts himself off and prepares to fight until his last breath, he hears Sam Wilson's familiar "on your left," and turns around to see Black Panther and the rest of the recently-revived heroes assembling through Doctor Strange and Wong's mystical portals.

The "Portals" sequence has had such a lasting impact that it might be difficult to imagine it playing out any other way, but co-director Joe Russo has now revealed that the original idea for the scene was quite different - and he had to fight for the version we saw in the finished film.