Jude Law Tries to Prevent a War on Muggles in' Fantastic Beasts: The Secrets of Dumbledore' Trailer

More Hogwarts! (Plus more mayhem.)

In the first trailer for Fantastic Beasts: The Secrets of Dumbledore, Mads Mikkelsen debuts his villain alongside the returning cast of Eddie Redmayne, Jude Law, Ezra Miller, Dan Fogler, Alison Sudol and Callum Turner.

"If you listen carefully enough, the past whispers to you," Law's Albus Dumbledore tells Redmayne's Newt Scamander as they join forces to prevent Grindelwald from killing non-magical people.

"The world as we know it is coming undone. Grindelwald is pulling it undone with hate," Dumbledore continues, urging Scamander, "If we're to defeat him, you'll have to trust me."

Elsewhere, Grindelwald's dark legion of followers prepare to rebuild the wizarding world in their image, as he tells them, "Our war with the Muggles begins today."

Mikkelsen stars as Gellert Grindelwald, a dark wizard and predecessor of Voldemort in the original Harry Potter franchise. Mikkelsen was cast in the role after Johnny Depp agreed to resign after losing his libel case against The Sun in November 2020 amid legal woes involving his ex-wife Amber Heard's assault allegations, which he has denied.

Depp said at the time that Warner Bros. had asked him to exit the role following the U.K. court's decision and that he had agreed to do so.

In June, Mikkelsen said he wished he could have spoken to Depp before taking over the role.

"I mean, obviously, they were going to do the film, and obviously he was not involved anymore," Mikkelsen told The Sunday Times at the time.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

"I didn't have a dog in that fight," he added. "I don't know what happened [in his private life] and I don't know if it was fair, him losing the job, but I just knew that the show was going on. And I would've loved to have talked to him about it if I had the chance, but I just don't know him in that sense."

"But they called me and they were obviously in a hurry, and I loved the script and so said yes. And I know it was controversial for many people, but that's just the way it plays out once in a while," he continued.

Mikkelsen also spoke about making the character his own.

"I didn't want to copy what Johnny had done. I think he's a masterful actor, so copying him would've been creative suicide," Mikkelsen said. "I had to figure out something that was definitely my own, and yet also act as a bridge to what he had done."

"My take is different, and the look is a little different, but we'll have to wait for the film's release to find out," the actor noted.

Fantastic Beasts: The Secrets of Dumbledore is in theaters April 15.