Ralph Fiennes shared the plot of '28 Years Later.' Here's everything we know about the sequel.

• In "28 Days Later," Cillian Murphy's character, Jim, wakes up from a coma after a zombie outbreak.
• Director Danny Boyle shot the sequel, "28 Years Later," on an iPhone.
• Actor Ralph Fiennes said that the story follows a young boy trying to save his mother.

"Oppenheimer" actor Cillian Murphy has reunited with director Danny Boyle for the long-awaited horror sequel "28 Years Later," two decades after his breakout role in "28 Days Later."

In the original film, Murphy played Jim, a bicycle courier who wakes up from a coma to find that the UK has been hit by the "Rage" virus, which turns people into zombies.

The infected, however, are not like the traditional slow, shuffling hordes of the undead. Instead, they sprint and scream while chasing survivors.

The film performed fairly well at the time, earning $84 million worldwide, according to Box Office Mojo.

Boyle's unique vision of a post-apocalyptic Britain led to a resurgence of zombie movies in the 2000s. Many took inspiration from Boyle's fast zombies, such as in the "Dawn of the Dead" remake, and "Zombieland."

While Boyle produced the 2007 sequel, "28 Weeks Later," the Juan Carlos Fresnadillo-directed film focused more on gory action, than the suspense-driven horror of the original.

In January 2024, The Hollywood Reporter confirmed that "28 Years Later" is in the works by Boyle and "28 Days Later" writer Alex Garland.

Here's what we know about "28 Years Later."

Cillian Murphy will be joined by Jodie Comer and Aaron Taylor-Johnson

Murphy has stated over the years that he would like to return to the franchise that kickstarted his career.

In February, he told Variety: "I've always said I would love to be involved because that movie changed everything for me and I have great affection for it and for those guys Alex, and Danny."

Murphy added: "So I'm really thrilled that we'll get the band back together to make this one."

In May, Sony Motion Pictures Group chairman Tom Rothman confirmed to Deadline that Murphy will reprise his role as Jim in "28 Years Later."

The Irish actor will be joined by British stars Jodie Comer, Aaron Taylor-Johnson, Jack O'Connell, Ralph Fiennes, and Erin Kellyman, per Deadline. Details about their characters are being kept secret.

In October, Fiennes told IndieWire that the story revolves around a young boy trying to save his mother in the north of England.

He said: "Britain is 28 years into this terrible plague of infected people who are violent, rabid humans with a few pockets of uninfected communities. And it centers on a young boy who wants to find a doctor to help his dying mother. He leads his mother through this beautiful northern English terrain.

"But of course, around them hiding in forests and hills and woods are the infected. But he finds a doctor who is a man we might think is going to be weird and odd, but actually is a force for good."

Ralph Fiennes said filming for "28 Years Later" and its sequel have finished.

In July 2024, set photos of Comer and "Young Royals" star Edvin Ryding surfaced online.

The pictures show the infected chasing Comer in the countryside, while Ryding's character appears to be a NATO soldier, judging by the patch on his uniform.

Earlier set photos from June also showed Taylor-Johnson with long hair and a beard while presumably running away from the infected.

The long-awaited sequel will arrive in theaters on June 20, 2025, and is the start of a new trilogy. Per Deadline, "Candyman" director Nia DaCosta was in talks to direct the follow-up in early 2024. According to Fiennes, the second movie has already been shot.

He said: "It's three films, of which two have been shot."

The title for the movie might have been revealed by the United States Copyright Office, which lists it as "28 Years Later Part II: The Bone Temple."

Danny Boyle used farm animals and an iPhone to film "28 Years Later."

A report by Wired, published on September 19, reported, citing unnamed sources, that Boyle shot the new sequel using an iPhone 15 Pro Max modified with additional lenses.

Wired also reported that "some scenes in '28 Years Later' were shot with action cams strapped to farm animals," although the outlet didn't reveal why.

Sony didn't immediately respond to a request for comment from Business Insider.

It seems likely that this unusual filming method will help capture a specific, energetic visual style during a chase scene involving the infected. But it's not clear whether the animals are specifically in the film, or if they're just an unorthodox filming tool.