The Flash Trailer's Super Meta Batman v Superman Easter Egg

The Flash isn't just going into the DC multiverse — it's going meta. The film's first trailer reveals super-speedster Barry Allen's (Ezra Miller) attempt to travel into the past to save his murdered mother (Maribel Verdú) and his wrongly-convicted father (Ron Livingston), only to break the universe by creating a world with no metahumans. Teaming up with his powerless younger self (Miller), a retired Batman (Michael Keaton), and the imprisoned Supergirl (Sasha Calle) to save the world from General Zod's (Michael Shannon) Kryptonian army, the fastest man alive time travels a decade into the past (as hinted by Barry 2's bedroom poster for 2013's Pacific Rim.) 

Also spotted in Barry 2's room is a poster for 2007's I Am Legend, set in post-apocalyptic New York City circa 2012. See it below:

In the Warner Bros. film where Dr. Robert Neville (Will Smith) is seemingly the last man on Earth, he's seen walking past a Times Square billboard advertising a Batman and Superman movie dated for 2010 — which wouldn't release in our reality until director Zack Snyder helmed 2016's Batman v Superman: Dawn of Justice.

"The reason that [the Batman/Superman movie poster] was there is that the producer and writer of I Am Legend, Akiva Goldsman, actually wrote an early, early [draft of what became Batman v Superman]," I Am Legend director Francis Lawrence explained in a 2016 interview. "We thought, 'Hey, what movies would it be fun to have up on the screen when the [Legend] plague hit?'"

Before the Dark Knight (Ben Affleck) and the Man of Steel's (Henry Cavill) title match in 2016's Dawn of Justice, studio Warner Bros. spent nearly two decades attempting the live-action Batman and Superman crossover that was little more than a "what if?" in 2007. 

Goldsman, who wrote 1995's Batman Forever and 1997's Batman and Robin, scripted a version where it was Jude Law's Superman and Colin Farrell's Batman battling it out in what Goldsman called "the darkest thing you've ever seen." 

"It started with Alfred's funeral, and Bruce has fallen in love and renounced being Batman. The Joker kills his wife, and then you discover it was all a lie. Just that the love itself was constructed by the Joker to break [Bruce]," Goldsman recalled in 2020 of his early 2000s script for the scrapped Batman v Superman. "It was a time where you would be able to get these sort of stories together in script form, but they couldn't quite land in the world. Somehow, the expectations of the object — whether they be audience or corporate or directorial — it wasn't landing quite in the way I think we imagined when we put them on the page."

Starring Ezra Miller, Sasha Calle, Michael Shannon, Ron Livingston, Maribel Verdú, Kiersey Clemons, Antje Traue, Ben Affleck, and Michael Keaton, The Flash speeds into theaters June 16th.