[Source: AP Entertainment]

There were many stressful things about making “The Flash” and getting it to theatres. It was shot in the middle of a pandemic.

There was isolation from friends and family for the 138-day shoot. There were A-list schedules to coordinate for cameos. There was a star in Ezra Miller who, after it wrapped, made headlines for legal run-ins amid a mental health crisis. And behind it all, a studio undergoing leadership changes and rethinking the whole DC Comics strategy.

But first, they had to figure out how to transport a two-ton Batmobile from Los Angeles to the U.K. amid a worldwide shortage of shipping containers in 2021.

This was not just any Batmobile, mind you. It was one of the originals from the Tim Burton movies that was needed for the grand return of Michael Keaton’s caped crusader after 30 years — a major production that also involved building, from scratch, a life-size replica of the Batcave.

Director Andy Muschietti and his sister, producer Barbara Muschietti, waited nervously for its arrival worried whether it would make it in time or just be stuck in the middle of the ocean. They breathed a sigh of relief when it made it ashore, briefly celebrated and moved on to the next problem: how to get it into the Batcave at Warner Bros. Studios Leavesden. Ultimately it involved a loading it onto a modified airport cargo truck that was lifted 20 feet (6 meters) in the air and “gently rolled” onto set.

It’s an apt if intentionally understated description of getting “The Flash” into theaters on June 16. Movie versions of the lightning quick comic book character have been in various stages of development since the late 1980s. One scenario had Ryan Reynolds starring and David S. Goyer directing; another had George Miller setting the stage for spinoffs and standalones with Adam Brody.

Then in 2014, things started taking shape as Warner Bros. plotted out a shared universe of DC Comics films, including a standalone Flash starring Miller as Barry Allen, who would first appear in “Batman v Superman: Dawn of Justice,” “Suicide Squad” and “Justice League.”

But even that wasn’t so straightforward, with disagreements over tone and scheduling conflicts making things complicated. Several writers and directors cycled in and out of developing “The Flash,” including Phil Lord and Christopher Miller, Seth Grahame-Smith, Rick Famuyiwa, Robert Zemeckis and John Francis Daley and Jonathan Goldstein, and release dates were pushed back. Ezra Miller even worked on their own treatment of a script.

The Muschiettis were finishing “It Chapter Two” when the studio approached them about “The Flash.” They didn’t concern themselves with the messy, marathon development history — they just wanted to figure out if this was worth several years of their life. In the story, Andy Muschietti found a compelling emotional core: The relationship between Barry Allen and his mother, who was killed when he was a child and whom he wants to go back in time to save. “Back to the Future,” which is referenced quite a bit in “The Flash,” was one of their favorite movies, too. They were in.

They told Keaton, who jogged to their lunch meeting in Brentwood, they wouldn’t be able to do the film without him. They wanted to find his Bruce Wayne in a place people wouldn’t expect. By the end of lunch, Keaton had agreed and jogged off.

Keaton’s Batman was also due to make a return in the standalone “Batgirl” movie which was ultimately shelved close to completion.

But then during the extensive post-production on “The Flash,” star Ezra Miller, also started making headlines for a string of arrests and reports of erratic behavior last year. They were arrested twice last year in Hawaii, including for disorderly conduct and harassment at a karaoke bar. In January, they pleaded guilty to a charge stemming from a break-in and theft of alcohol at a neighbor’s home in Vermont. They avoided jail time but paid a $500 fine and got a year of probation, agreeing to abide by a number of conditions including continued mental health treatment.

Though some questioned whether “The Flash” should be shelved, the studio remained committed to releasing it on June 16 even without its star on the promotional circuit.

While early hyperbole abounded with people like Gunn calling it one of the best superhero movies he’d ever seen, reviews have indeed been mostly very positive with lots of praise for Miller’s dual roles.

There are even rumors that the Muschiettis’ DC relationship will continue with future films. But right now, the focus is “The Flash.”