• The first trailer for "28 Years Later" has dropped, and shows survivors in post-apocalyptic Britain.
• Director Danny Boyle reportedly shot the sequel to "28 Days Later" on an iPhone.
• Actor Ralph Fiennes said that the story follows a young boy trying to save his mother.

The first trailer for "28 Years Later" has dropped.

The film sees "Oppenheimer" actor Cillian Murphy reunite with director Danny Boyle for the long-awaited horror sequel 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 fast zombie-like creatures.

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.

But judging by the brutal first trailer, it looks like "28 Years Later" will be a mix of both. Here's what we know about the sequel.

The "28 Years Later" trailer depicts a brutal vision of post-apocalyptic Britain

On December 10, Sony released the first trailer for the highly anticipated sequel, showing what post-apocalyptic Britain looks like and who has survived the Rage virus.

It shows characters played by Aaron Taylor-Johnson and 13-year-old Alfie Williams as two survivors living in a heavily defended island community that has become a safe haven.

When they venture out onto the mainland, they're chased by the infected. There are also glimpses of other cast members, including Jodie Comer and Ralph Fiennes.

The footage is narrated using a creepy recording of Rudyard Kipling's poem "Boots," which the military also uses to train elite soldiers.

One scene shows totem poles made out of bones and skulls, which could be where "28 Years Later Part II: The Bone Temple," the sequel which doesn't have a release date yet, gets its title.

Sony also shared the film's synopsis, which reads: "It's been almost three decades since the rage virus escaped a biological weapons laboratory, and now, still in a ruthlessly enforced quarantine, some have found ways to exist amidst the infected. One such group of survivors lives on a small island connected to the mainland by a single, heavily-defended causeway.

"When one of the group leaves the island on a mission into the dark heart of the mainland, he discovers secrets, wonders, and horrors that have mutated not only the infected but other survivors as well."

Cillian Murphy is 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 joins British stars Comer, Taylor-Johnson, Fiennes, Jack O'Connell, 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 on the "28 Years Later" sequel, "The Bone Temple," has also finished.

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.

The title for the second movie, "The Bone Temple," was revealed by the United States Copyright Office.

According to Fiennes, the follow-up has already been shot. He said: "It's three films, of which two have been shot."

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.