Avengers: Endgame - 20 Things We Learned From The Director's Commentary

4. The "I Love You 3,000" Callback Was Dubbed In Post-Production

Perhaps the most affecting moment in Endgame's epilogue occurs when Tony's family plays a message he recorded into his Iron Man helmet the day before the time heist.

He signs off by telling his daughter Morgan (Alexandra Rabe), "I love you 3,000", in a devastating callback to her telling her father the same in the first act of the movie.

It's a moment so perfect it seems like it was always part of the plan, but according to Joe Russo it was an incredibly late addition, so late in fact that it had to be added deep in post-production through ADR dubbing - hence why Tony Stark speaks it off-screen.

Thankfully it doesn't undercut the emotion, even if it's a shame we never got to see Robert Downey Jr. deliver the line in person.