Avengers: Endgame provided fans with some closure for Tony Stark and Iron Man. Robert Downey Jr.'s portrayal of the iconic character was heartbreaking for Marvel Cinematic Universe fans, but it was also epic at the same time. When the Russo Brothers were in the editing room, the conclusion of Endgame needed something more from Stark, but they weren't sure just what it was until editor Jeff Ford gave them the line that they needed, which required an immediate call to RDJ for a quick reshoot.

The line in question is obviously: "I am Iron Man," which Tony Stark says as he snaps his fingers with the homemade Infinity Gauntlet. Thanks to Robert Downey Jr.'s assistant Jimmy Rich, we now have some brief, albeit powerful, footage from behind-the-scenes when that moment was being captured. In addition to watching RDJ against a green screen delivering the line and snapping his fingers, it's also notable for being the last scene the Russo Brothers directed for Endgame. There has been a great deal of set footage hitting social media over the last month, but this is some of the best so far.

RELATED: LEGO Reveals Avengers: Endgame Set Featuring Bro Thor

The "I am Iron Man" line goes back to 2008 and originally was not included in Endgame. While working hard in putting the final edit together, the Russo Brothers discovered the snap scene needed something else from Tony Stark. "He has to say something. This a character who has lived and died by quips," said Anthony Russo. It's at this moment editor Jeff Ford delivered the line to the directing duo. Apparently the line made perfect sense right away and the Russos were ready to shoot.

Thanos may be inevitable, but Tony Stark is Iron Man. While Infinity War was the Mad Titan's movie, Endgame saw the original six Avengers doing whatever it takes to make sure they did not make any mistakes the second time around. The result is sacrifice on the part of Earth's Mightiest Heroes. Black Widow sacrificed her life for the Soul Stone and Stark sacrificed his life when he strapped on his makeshift Infinity Gauntlet to save the universe. These were some hard scenes for fans to watch, but they were rewarding at the same time.

Avengers: Endgame is currently the second highest grossing movie of all time after some record breaking early success. However, the early box office numbers quickly began to slow down and the movie is currently a little over $40 million away from becoming the highest grossing movie of all time, dethroning James Cameron's mighty Avatar. With an Endgame re-release in theaters next week, Marvel Studios and Disney are hoping they can get over the finish line to become the box office champion. While we wait to see if they can achieve their goal, you can check out the Endgame behind-the-scenes footage below, thanks to Jimmy Rich's Instagram account.