Back in 2015, Back to the Future nostalgia was at an all time high, as that was the year Doc Brown travels to in Back to the Future 2 to save Marty's kids, and repair the timeline. Since then, the franchise has cooled considerably, but that doesn't mean people aren't still watching these time travel adventures obsessively. And now one of the saga's bigger fans has discovered an Easter egg that has gone mostly unnoticed for the past 27 years. While some have probably spotted it, it's never been well documented. At least, not until now.

Director Robert Zemeckis helped pioneer the new Easter egg Renaissance that we experience in most big budget franchise outings nowadays. The three Back to the Future movies are loaded with them. So many that some are still being discovered some 27 years later. Such is the case with a bandit mask used by Doc Brown during Back to the Future 3's big train hijacking scene. One fan noticed something quite familiar about this rag, sharing it on a Reddit post over the weekend.

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But the Easter egg is actually an Easter egg held within an Easter egg, one that first popped up in Back to the Future 2. When Doc and Marty travel to the year 2015, Doc is seen wearing a futuristic shirt that quite well suits his personality. It also acts as a bit of foreshadowing for what's to come in the Western-themed final outing. While discussing the ramifications of interacting with various individuals in the future, and how it will further disrupt the space time continuum, he has on a colorful and cartoony shirt that features trains set against a yellow sunset, horses galloping alongside, with pillowy smoke spewing from the smokestack. Familiar scenario, right.

Upon initial viewing, most fans didn't think too much about that shirt, or how it was a spoiler for Back to the Future 3's final act. But as is the case with Doc Brown, the scientist never wastes material. And this all ties into Mr. Fusion, which recycles for power. Only, Doc didn't throw this shirt in to help fuel his further adventures through time. He instead must have had it stashed in the back of the DeLorean. As he is seen using it once again in Back to the Future 3. Only here, it has been repurposed into a bandit mask, which Emmett wears across his face when he and Marty take over the train. Marty is wearing a dark grey scarf in this call back scene.

Most didn't ever notice that Doc Brown was putting his shirt from 2015 back to good use in Back to the Future 3. But there it is. And to back up this claim, displays of both props shown side-by-side clearly confirm that Doc's bandit rag is made from the same material as the shirt. Which was created specifically for the movie by its costume designer. Most chimed in on Reddit that they'd never ever noticed this fun call back. One fan says this about the Easter egg, which truly is a big spoiler, years before spoilers were such a big thing in modern social fan club circles.

"[The] shirt depicts a train, two horses, and a car. All being transportation that aided Marty to return to 1985. A bonus is that the images point left, or west on a standard map."

In the final moments of Back to the Future 3, when Doc and Marty have to stop the train, the duo mount horses and gallop towards it. They then pull off a very apologetic heist. It just goes to show that no matter how many times you might watch a movie, there are always new things to discover.