We were already cautioned that Marvel Studios will closely guard plot details about Avengers: Endgame, with the marketing campaign perhaps revealing no footage from beyond the first 20 minutes of the eagerly anticipated sequel. But with the debut on Sunday of the film's 30-second Super Bowl spot, some fans are wondering just how far the studio is willing to go to preserve secrecy.

It's not a question of what's left out of the promo, but rather who may have been removed from the footage included.

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Fifteen seconds in, Steve Rogers, Natasha Romanoff, Bruce Banner and James Rhodes walk outside of Avengers Compound, seemingly in reaction to something (or someone) arriving in the night sky. That provides plenty of fuel for speculation, but so, too, does the conspicuous gap between Banner and Rhodey.

Avengers-Endgame-Super-Bowl-spot-missing-character

Now, if this were a commercial for virtually any other film, we probably wouldn't think twice about the unusual composition of the sequence. But this being Marvel, we can't help but wonder: Is there a fifth character who was edited out of the Super Bowl spot in order to preserve a plot detail?

It certainly wouldn't be the first (or even second) time the studio has misled fans in the marketing of a film. In fact, it was only three years ago that the Super Bowl TV spot of Captain America: Civil War showcased the first look at Team Cap and Team Stark preparing to face off on the tarmac. However, the footage didn't include Spider-Man, who was in the sequence in the actual film.

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More memorably, trailers and TV spots for Avengers: Infinity War hid the number of Infinity Stones in Thanos' possession, and went so far as to depict the Incredible Hulk running into battle alongside his allies in defense of Wakanda. But, of course, the Hulk only appears in the film's opening scene, and never returns, despite Banner's best efforts. Directors Joe and Anthony Russo even admitted to employing misdirection in the marketing to stay ahead of the fans.

Hulk in Avengers; Infinity War promo

As that sleight of hand is a big part of Marvel's bag of tricks, we shouldn't take the Endgame trailers and TV spots at face value. It's certainly possible the scene in question only includes those four characters. But the gap between Rhodey and Banner is certainly notable, as it's difficult to come up with an explanation for why the sequence should be framed in this way ... other than someone is missing from it.

But who could it be? Is Captain Marvel already part of the team at this point? Did Tony Stark somehow make it back to Earth in time to rejoin his teammates? Or is some other character being kept under wraps?

It might be nothing. But, then again, it could definitely be something. Watch out, Marvel: Fans are definitely on to you this time.

Directed by Joe and Anthony Russo, Avengers: Endgame stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Chadwick Boseman, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie. The film arrives April 26.