'Avengers: Endgame' Spoilers: 11-Year-Old Easter Egg May Reveal the Ending

Over the years, Iron Man fans have noticed a strange Easter egg across the Marvel Cinematic Universe: Tony Stark’s left arm constantly seems to be a source of pain for the billionaire superhero. It might just seem like a fun recurring gag, but a new fan theory suggests that Tony’s left arm could be the key to stopping Thanos once he slides it into the Infinity Gauntlet in Avengers: Endgame.

Inverse is posing a few theories of its own with Inverse String Theory ahead of the premiere of Avengers: Endgame.

The key to this theory, from redditor u/Dolly_Bakels, comes from one of the final scenes of Infinity War when Thanos finally snapped his fingers and dusted half of the universe. As eagle-eyed fans noted, the scale of that Decimation caused some serious damage to the gauntlet, and the first trailer for Avengers: Endgame revealed that Thanos was also injured as a result.

“His left arm got all shriveled and looked decayed,” u/Dolly_Bakels writes. “Now what if Tony’s arm did the same thing, but in the past, where he doesn’t remember it ever happening?”

The theory, which hinges on our assumption that Avengers: Endgame will introduce time travel to defeat Thanos, goes on to explain that Tony Stark and a group of heroes could travel back in time, steal the Infinity Stones, and then use them to undo the Decimation with a second snap. However, a side effect of that plan could be the damage caused to Iron Man’s arm after he wields the Infinity Gauntlet, and that damage could travel through time in either direction regardless of when it happened — especially if the Avengers have already distorted the timeline by messing with it earlier in the movie.

Tony’s also been seeing Thanos in his head ever since the Battle of New York in the first Avengers movie. This distinct connection could allow him to wield the Infinity Gauntlet.

It’s an interesting theory that would provide some great closure to a very long-running MCU Easter egg, but as commenters on Reddit quickly noted, there are a few holes in this argument. For one thing, every injury to Tony’s left arm can be explained by something that happened in that movie. In Iron Man, he gets blasted by a tank, in Captain America: Civil War, he falls roughly 100 feet and lands on his left side, and the list goes on.

It’s also worth noting these left arm injuries predate the first Avengers movie, though, like we said, it’s possible his Snap-related injury could reverberate back in time thanks to the power of the Infinity Stones.

Regardless of what it means for his left arm, it’s definitely possible that Iron Man could be the one to wield the Infinity Gauntlet for good in Avengers: Endgame. He’s certainly earned it after 11 years of on-screen heroics.

Avengers: Endgame hits theaters April 26, 2019.