Black Widow dropped her signature red hair for the first time in Avengers: Infinity War, opting instead for something starkly different: a bleach blonde bob. The new look was clearly an effort to better disguise herself after the events of Captain America: Civil War left her going underground with Steve Rogers and the rest of his loyal band of ex-Avengers. (You can’t just rely on a baseball hat and hoodie forever in the Marvel Cinematic Universe…)

While it was a noticeable change, Natasha's new hair didn't garner anywhere near as much attention as Steve's glorious new beard. Probably because, by now, we know that a new MCU movie featuring Scarlet Johansson's super spy always means a wig change. But, in the case of the final trailer for Avengers: Endgame -- the feverishly-anticipated sequel to Infinity War -- the change between styles happens on-screen. One moment she's blonde and the next she's back to her old red hair. Symbolically, this falls in line with the "back to basics" theme of the film -- taking us back to the original Avengers line-up of the first.

RELATED: Avengers: Endgame - Marvel Really Wants Us to Think Nobody's Coming Back

Black Widow in Infinity War

While some theorists might interpret that as a clue that some time-jumping is happening, or possibly even flashbacks, the real answer is probably much simpler than that. Let's go through each scene Black Widow appears in the latest Endgame trailer in chronological order and use these hair changes to piece together the film's potential timeline.

Avengers: Endgame trailer

When we first see Natasha, she's talking to Hawkeye/Ronin in a rain-soaked city. Judging from their expressions, this is likely the first time they’ve seen each other since The Snap. Clint's edgier makeover strongly suggests his family, who we spent significant time with in Avengers: Age of Ultron didn't survive Thanos' brutal cull. This is also the first we see of Natasha's hair change since Infinity War to a darker, longer style.  

Avengers: Endgame trailer

Later in the trailer, we see Natasha and Clint flying into New York. She still has the same red hair so we know this scene happens after their reunion and presumably she’s bringing the wayward archer home. You can also clearly see streaks of blonde in her hair, so the easy assumption is that she’s growing the blonde dye out -- meaning at least a few months have gone by (maybe more considering how much longer her hair is) since the events of Infinity War.

RELATED: Avengers: Endgame Trailer Voiceover May Hide a Major Plot Clue

Avengers: Endgame trailer

Next, in the scene where Nat is doing some angsty target practice, her hair is still blonde but falls below her shoulders, so this scene is likely happening not too long after Infinity War, but AFTER Captain Marvel shows up, because in the post-title card scene, she’s seen next to Thor and Carol with the blonde bob.

Avengers: Endgame trailer

These two scenes are perhaps the most interesting reveals because it seems as though Captain Marvel's arrival must occur fairly early into Endgame. Rather than make a grand, surprise entrance towards the movie's climax when the team will likely be taking their final stand against Thanos as some predicted, Carol's presence could be the thing that galvanizes our downtrodden heroes back into action.

Avengers: Endgame trailer

Finally, when we see the remaining Avengers all together in their new white suits, she’s got long red hair. Plus, Mohawkeye is in tow, confirming this scene takes place later than the previous ones.

RELATED: Endgame Trailer All But Confirms Avengers' Outfits are Quantum Realm Suits

Notably missing in the line-up are Rocket and Captain Marvel. They could just have been cropped out of this particular scene for the trailer, or the team could be attacking Thanos on two fronts since we know that Carol has definitely been recruited at this point thanks to Natasha's telltale blonde bob. (Here's hoping she and Rocket have gone searching for a missing "cat" that could come in real handy in a pinch...

Directed by Anthony and Joe Russo, Avengers: Endgame stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner, Don Cheadle, Paul Rudd, Brie Larson, Karen Gillan, Danai Gurira, Benedict Wong, Jon Favreau and Bradley Cooper, with Gwyneth Paltrow and Josh Brolin. The film arrives April 26.