Avengers: Endgame needed only a few days in theaters to shatter all expectations, as well as many box office records. With a global haul of $1.2 billion after its first five days in theaters, Endgame is Marvel’s biggest movie to date, and it’ll likely make even more money by the time its theatrical run ends. The fact that many fans will want to see it a second time will help, and that’s understandable considering all the details that Marvel packed in the movie.

There are so many Easter eggs and callbacks to previous Marvel films that it’s very likely you’ll miss some of them, including a few crucial ones. One of them concerns Captain America, and it might provide a clue about the future of the MCU. But before we get into it, I’ll warn you that several spoilers will follow.

To understand why Captain America’s arc makes perfect sense in Endgame, you also need to understand one of the film’s most controversial plot points. That’s time travel, as MCU’s way of dealing with the concept differs from what you’ve seen in other movies. Time travel in the MCU isn’t like Back to the Future, and we’ve explained it in great detail. The gist of it is that you can’t change the future by modifying the past. However, any change in the past can create a timeline that will follow a different course than your own timeline. Professor Hulk and The Ancient One do a great job explaining what Marvel wants out of time travel in its universe.

These time travel rules worked just fine until the very end of the movie, where Marvel seemed to break them. An aged Steve Rogers appears on a bench, surprising everyone but Bucky. We learn that Cap decided to live his life, just as Tony had suggested, having settled somewhere in the past — and we think we know precisely where Steve might be. But it’s unclear from that scene whether he lived in the main MCU timeline, or whether he branched off a different one, where he and Peggy danced, got married, and had kids. The Russo brothers have since confirmed in an interview that old Steve did indeed come back from an alternate timeline.

In the same scene, we learn that Steve brought a new shield with him to pass on to the next Captain America: Sam Wilson. Marvel just explained the shield comes from an alternate reality, but why does it look different? That’s the detail you might have missed. Captain America brought back a shield that’s almost identical to the one he used in all the previous movies… but it doesn’t have quite the same design.

A Redditor was quick to notice the detail, and he’s absolutely right. I’ve seen the movie a bunch of times, and didn’t realize it was a new shield until I saw this post. That’s probably because I was too absorbed in the dialogue, trying to figure out clues from Cap’s talk with Sam. As fischflosse points out, the white circle does have a line running through the middle. Moreover, in the center of the star, there’s a smaller star.

Let’s check out Cap’s shield from A Winter Soldier:

Image Source: Marvel Studios

Now let’s look at the shield he’s using throughout Endgame. This is the shield he just got from Tony, which is to replace the shield that Thanos manages to break with his epic sword in Infinity War:

Image Source: Marvel Studios

Finally, let’s look at the shield Cap passes on to Sam in that emotional scene at the end:

Image Source: Marvel Studios

Cap does tell Sam that this shield belongs to the new Captain America, and the fact that it has a different design is a clear indication that it is indeed a new shield that Steve made for Sam. After so many years wielding it, Steve knows exactly what the shield looks like, so it’d be easy for him to provide manufacturing instructions to whoever built it to create an exact replica of the original. Steve doesn’t want that. He wants Sam’s shield to be unique, while keeping true to the identity of Captain America. This might suggest that if Bucky were ever to get a shield in the MCU, he’d have a personalized version of it as well.